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View Full Version : Project : 88 Prostar 190 - 454 Indmar rebuild time


jconover
07-01-2010, 04:02 PM
Just purchased a 1988 Prostar 190 with an Indmar 454 - 897 hours on the run meter. Starting this thread to tap the expertise of the community and document my process for others to benefit from.

This boat had a former life as a show skiboat, though the prior owner was not said show-ski owner. Took the boat out for a pull before purchasing -- she rumbled like any good 454 should. PO had a mechanical inspection sheet from a year prior (he had a new carb and water pump put on the engine for $1400), so I bought in confidence for $6700. PO suggested I change oil and tranny fluid, as he had not done so the year prior (no hours on the boat this year yet).

Took boat skiing with my buddies a few days later, pulls like a monster (hang on tight). Idle was set a little high, and engine idles well but sounded like it had a custom cam (wouldn't surprise me given the original application, but read on)

Took boat to my local trusted boat mechanic (non-MC dealer but does a lot of I/O and outboard work, mercury/yamaha trained wrenchmonkey) to change oil and give it a once over. Took out spark plug #1 and immediate had that sinking feeling - plug was shiny new, no carbon. Compression test and a little messing around later revealed that cyl#1 intake valve is in the permanently open position. So i'm planning to pull the exhaust manifolds and heads tomorrow (going skiing on my other boat tonight, it's too nice to start wrenching tonight).

I've tore down a few chevy and ford automobile engines, but I don't do much of the rebuild work myself -- too many specialized tools and tiny parts in the valve train. That said -- any old-hat experience here on things to look for or ways to be efficient in this process?

Second - I really want to avoid pulling the block out of the boat if I can avoid it. I'm hopping I can have the top half of the engine rebuilt while leaving the block in place. Again, any commentary here on prior success or failure.

Third - I see that one of the head bolts has been snapped off just inside the head (part is still sticking out, below flush on the head). I am guessing I'm going to need to have that drilled out and/or re-tapped. Any good advice here?

Fourth - While I am ripping it apart... what else should i look/check for. (inside)

Fifth - Along the same lines - outside the engine - since i'm investing in rebuilding the top half - anything else that I should dig into? The distributor looks old, but inside it seems to have electronic ignition (can take pictures). It has an electronics unit, but I still see a condenser in there too. Scarring on the pickups doesn't seem too bad; my local beer drinking engine buddy said it he might replace the distributor rotor, cap, and wires; i wasn't really sure it needed it. Underneath, the weights and magnets look rusted, but the move smoothly and easily. Not really sure i want to mess with the distributor, might be wasting $$. (again, can take pictures when I start pulling it apart)

Sixth - if i'm going to tear the top of the engine apart, i'm assuming i'm going to need one of these? - http://www.iboats.com/Chevy-Marine-454-Head-Gasket-Set-Sierra/dm/cart_id.894963126--session_id.738288633--view_id.174853

BrianM
07-01-2010, 04:11 PM
Sounds like you probably just need to have the heads worked. No need to take the engine out. Just take off the intake and exhaust manifolds then take the heads off and then have your local machine shop rebuild them for you. Besides that I would swap out the points to electronic if it hasnt had that done and replace all of the 'tune up' parts (cap, rotor, plugs wires and filters) then call it a day.

jconover
07-01-2010, 04:32 PM
Some pictures of the boat, accessories, and hull damage.

jconover
07-01-2010, 04:33 PM
A few more shots including a few of the motor

jconover
07-01-2010, 04:44 PM
And a few more of the other end.

jconover
07-01-2010, 04:52 PM
Wow that gets tall in a hurry.

Looking for a few more bits of advice:

#1) The pylon - Anyone seen one of these before? Any idea who made it? It makes it hard to put a skylon on there. Not sure if I want to invest in a tower for this boat, given I really need an open bow boat in a few years (4 kids, ages 5,3,2, and -1 ->due july 17). Plan to get this one in great shape and then sell it to buy up to a open bow, 205 or hopefully a 214 (X-14?)

#2) shots 3 and 4 - a tiny bit of gelcoat damage below the water level. recommendations for repair? I plan to take it to someone, anything I should look for? I live in northeastern wisconsin btw, if anyone knows a great glass guy.

#3) shots 5 and 6 - someone biffed her in the nose and tail. i am getting the nose fixed next week, it drives me nuts what a half-ape job someone did on that. Note that the blue color is automotive paint. Someone did a good job, and I'm hemming and hawing about wetsanding down through the paint to the original gelcoat as a winter project; hard to guess why he painted it blue, if he was covering up damage, or just too lazy to work it out the hard way.

#4) shot #9 and 10 - those water hoses don't look up to spec. I saw some really slick ones in another post on an MCX, complete with mastercraft logos. Any idea where those came from?

#5) shot 11 - teak - eww. Going to try the harold (highly patient) method over the winter. Thanks for the geat discussion in the forums on that one

#6 - show 12 - the barefoot boom. Apparently manufactured by KW Barefoot Boom. Never seen one like it before :-)

DooSPX
07-01-2010, 09:08 PM
Wow that gets tall in a hurry.

Looking for a few more bits of advice:

#1) The pylon - Anyone seen one of these before? Any idea who made it? It makes it hard to put a skylon on there. Not sure if I want to invest in a tower for this boat, given I really need an open bow boat in a few years (4 kids, ages 5,3,2, and -1 ->due july 17). Plan to get this one in great shape and then sell it to buy up to a open bow, 205 or hopefully a 214 (X-14?)

#2) shots 3 and 4 - a tiny bit of gelcoat damage below the water level. recommendations for repair? I plan to take it to someone, anything I should look for? I live in northeastern wisconsin btw, if anyone knows a great glass guy.

#3) shots 5 and 6 - someone biffed her in the nose and tail. i am getting the nose fixed next week, it drives me nuts what a half-ape job someone did on that. Note that the blue color is automotive paint. Someone did a good job, and I'm hemming and hawing about wetsanding down through the paint to the original gelcoat as a winter project; hard to guess why he painted it blue, if he was covering up damage, or just too lazy to work it out the hard way.

#4) shot #9 and 10 - those water hoses don't look up to spec. I saw some really slick ones in another post on an MCX, complete with mastercraft logos. Any idea where those came from?

#5) shot 11 - teak - eww. Going to try the harold (highly patient) method over the winter. Thanks for the geat discussion in the forums on that one

#6 - show 12 - the barefoot boom. Apparently manufactured by KW Barefoot Boom. Never seen one like it before :-)

WOW!! Your up and coming baby is due on my Birthday!! Your boat looks like a great project! a 454 w/ a SLOT! thats a tug I bet.

Rockman
07-02-2010, 09:22 AM
Where are you located in Wisconsin?

You definitely have a unique boat with the 454!

Keep the boat as is in terms of not adding a tower. Towers to the late 80s series boats change the whole look of it, IMO.

My advice would be to concentrate on the engine concerns you have and worry about the cosmetics later.

I am interested in hearing about your progress. Congrats on the soon-to-be-addition to the household!

Good Luck on your new purchase!:steering:

jconover
07-02-2010, 11:57 AM
greater Green Bay area.

Got the exhaust manifolds off this morning. waiting for the service manual for the indmar to show up (UPS shows "en route to delivery"). Anyone know whether you need to pull the carb and/or distributor to remove the intake manifold. I'm probably going to mark and remove the distributor just in case; i seem to remember breaking one in a prior project trying to remove the intake manifold without pulling the distributor.

BrianM
07-02-2010, 12:39 PM
454 and a Powerslot. That boat has got to be a monster.

jconover
07-02-2010, 03:31 PM
So on the advice of my local greasemonkey, I stopped before pulling off the intake manifold and pulled the valve cover. Low and behold, the nut holding the rocker arm on the #1 cylinder had backed off. Now, I've never seen this happen before, but what's more weird is that the nut was finger loose. backing it up another half turn, it got tight, but I could thread it down 3 or 4 turns before it got too hard to turn with my fingers.

The rocker arm had landed sideways and was sitting in a position where the pushrod could move freely and unobstructed. I pulled the pushrod out, it seems perfectly straight. So next step: get a new nut and re-attach the rocker arm in the right position and see if she behaves.

Quick Question: Anyone ever seen a rocker arm retaining nut come loose? I wonder if the stud is slightly stripped. Doesn't look like it, but the way that nut spins freely through the middle has me wondering.

87MCProstar
07-02-2010, 03:36 PM
454 and slot, i'm jealous...would love the pull and sound of a big block. what is the top end of that baby?

jconover
07-02-2010, 03:50 PM
I am seriously tempted to have a vinyl name cut for it --- "The Beast". It sounds simply awesome. I'm still not certain if the engine has a custom cam or not, but it has that wonderful put-(pause)-PUT-put-put put-put-(pause pause)-PUT sound that a cam'd engine makes. I took it skiing the night I got it (test run) and we got it up to about 46 mph with a 14x20 3-blade (4500 rpm, right in the sweet spot). I just received a 14x20 4-blade which i'm hoping cuts down the prop wash a bit... it's soft, but I hate that little bump in the middle of my otherwise perfect wake :-)

Also, noting the rest of this thread, that top end was achieved on 7 cylinders. The #1 plug was clean as a whistle, I don't think it has been fired since they were changed. Once I get that rocker re-installed, I'm guessing there are a few more ponys to be had from the beast.

Only trade-off with the engine is the noise volume at throttle up when you are sitting in the back seat. You can't really speak to the person in the front seat unless you yell. Of course, with the wind whipping by, i'm not sure that it would matter anyways. She's a throaty, noisy beast.

jconover
07-06-2010, 12:21 AM
No easy fix here. Did a detailed compression check on the #1 cylinder after fixing the rocker arm. Still leaking air through the intake valve. Time to pull the heads.

Look what I found... 1 cracked intake valve and a few small pits in the top of the cylinder.

I know what to do with the valve... What about the cylinder? I can't find any scoring or other damage to the cylinder wall, so we're just talking about a few small pits in the top of the cylinder.

jconover
07-07-2010, 03:06 PM
Rebuild shop got back to me today. Heads are good, no cracks, but looks like this is the first head service this engine has had. Valves are generally depressed, starboard head gasket was extremely worn and ready to blow. New valves all around plus head gaskets running me $778, plus $522 in labor for the seat grinding, head resurfacing, valve installation, etc.

87MCProstar
07-08-2010, 10:36 AM
that hurts a little, but still less than a new set of heads though right?

jconover
07-08-2010, 03:08 PM
Hah! True enough.

Hey - I'm having trouble locating a distributor cap and rotor for this engine.... anyone know where to get parts for a Delco-Remy distributor? I was eyeing up the Mallory replacement distributor as well, but I'm not sure I want to spend $335 to replace a perfectly working distributor...

Mr_Woodcock
07-08-2010, 03:18 PM
try skidim.com they also have very good customer service and will provide you with the right part.

jconover
07-13-2010, 02:14 AM
OK - heads rebuilt and reinstalled. Boy them exhaust manifolds are HEAVY.

Reinstalled everything to its original position and started engine break in procedure. Engine starts and runs nicely, but hauling out the timing light has got me completely confused.

Here is my procedure and situation:

Info: Chevy/Indmar Big Block 454 standard (LH) rotation. Delco-Remy distributor with after-market electronic ignition and ballast resistor.

Procedure:

1. Brought Engine to Top Dead Center (verified visually before I installed the heads), and later (troubleshooting) using the finger-on-plug#1 compression-test method.

2. Installed Distributor, aligning rotor to point at #1 plug terminal. Note: Distributor can only be installed one of two ways due to keyway on oil pump. I learned through trial and error that oil pump keyslot can be rotated with a long screwdriver to apply correct alignment to rotor. Rotor turns clockwise in this engine.

3. Verified plugs are attached in correct firing order, and to correct cylinders. Firing order is 1-8-4-3-6-5-7-2.

4. Verified that timing mark is indeed aligned to engine top dead center. Harmonic balancer has not slipped; timing mark aligns with top of compression stroke.

5. Secured distributor, snug but loose enough to move with my hand

6. Timing light is attached to plug #1.

7. Attempted to turn engine over, adjusted distributor to 10 degrees before top dead center (BTDC). Turned on ignition, primed fuel system and attempted to start engine. No ignition. Engine turns merrily but does not start. Mental note: wears battery down quickly.

8. After significant consternation, rotated distributor randomly while trying to start motor. Eventually got motor to start. Measured timing by dialing in timing advance on Snap-On timing light. Advance on timing light reads 38 degrees (e.g. firing about 28 degrees after top dead center, if I understand this correctly) . Engine idles at 1200 rpm. Fine tuning distributor (advancing further, turning distributor counter-clockwise) settles engine at about 800 rpm when engine is up to speed.

Took the whole thing apart and repeated this procedure. Re-verified plug wires.

I have no idea why this engine is even running at 38 degrees advance at idle. It seems to power through the throttle curve to 3000 rpm (still in break-in period, don't want to push beyond that), and timing advanced further (weights and springs are working) as engine RPMs increase.

Can someone tell me what I am missing/doing wrong here? It doesn't seem like this is right at all.

thatsmrmastercraft
07-13-2010, 08:54 AM
You installed the distributor one tooth off. Played that game before.

jconover
07-13-2010, 01:22 PM
Wouldn't turning the distributor cap compensate for that, though?

JohnnyB
07-13-2010, 01:36 PM
I am very familiar with this boat. It has been for sale for 3 years and has not moved from its spot on hwy 41 by Mid Valley GC....I've looked at it a couple of times. Who was the original owning show team, any idea??

I live on the Fox North of the WT Bridge but South of the Little Rapids Lock/Dam. The night you test drove "the beast" we were behind you at the launch with the Black on White Mastercraft with the tower (Barefooters).

Was that you out there with your motor cover up last night??? Was on the way to my daughter's soccer game, otherwise I would've drove out to help ya out.

What are you using the boat for? Skiing, footing, wakeboarding, foiling????

Where in/around Green Bay do you live?

Good luck! Welcome to the board!

-John

JohnnyB
07-13-2010, 01:42 PM
BTW,

I know a good fiberglass guy that has a mobile repair shop and does great work at a reasonable price. PM me if you want his info.

jconover
07-13-2010, 10:52 PM
Has it really been for sale for 3 years? 'tis a shame, that guy didn't take very good care of it. Apparently he had a new carb put on it 3 years ago, and I don't think he's run it since then. The timing was waaaaay advanced, and he had an automotive distributor in there (complete with vacuum advance). The #1 intake valve was cracked. Still pulled like a beast. It should be real nice by the time I get done with it.

I am not certain who the original show team was; i could pull the DNR history if I really wanted, but he was at least the third owner. MC told me this is a fairly rare boat - they didn't make many with 454's in 88.

I live up the road a bit north of Little Rapids in Lawrence; not waterfront property unfortunately, so I drive down to WT. I've found WT to be much calmer waters due to the high river banks there - I can ski that section of river most days regardless of wind unless the wind is right out of the NNW.

I've seen you out footin' it. I am a slalom guy right now, but I intend to learn to barefoot now that i have a boat that can do it. I've been skiing out there on my ProMag/181 outboard since 2004. You might have seen me cutting out there the last few years. I carry my two older kids (3 and 5) many nights now too, along with 2 or 3 other guys.

Yeah, that was me out there with the motor last night. I head out with the expectation that I would be checking the timing advance at 3K RPMs, but when i put the gun on the harmonic balancer, I couldn't even find the line (Doh!). Funny, it idled well enough though, and it powered through the curve to 3000 rpm without too much effort. It was running well enough to motor around, but we were sitting there in the current diddling with the distributor, and I'm thinking to myself.... i probably shouldnt pull this thing out while there is so much current and me with no anchor.

I've done a lot of research on installing distributors -- I also ordered a new marine distributor today, so i'm going to drop that it. I did all the normal stuff i knew (engine at TDC, rotor pointing at #1. What I think I missed is that you are supposed to align the mark on the spline to the dot on the shaft; and then the whole thing is apparently supposed to point at the 'rest spot' on the distributor (the place where the key lines up with the distributor cap). I missed this last set of facts, so I'm not sure that my timing was actually that far off, but rather it wasn't actually aligned to the timing marks. We'll see tomorrow.

Luv2Ski
07-14-2010, 10:37 AM
It is also possible that the outside section of your damper has rotated relative to the center.

This is happens on occasion on the two-piece dampers as the rubber is simply press-fit in there.

You can check this with a piston stop. It is a little device that you thread into the #1 spark plug. You turn the engine one way (BY HAND) until the piston lightly taps it, make a mark on the damper, then turn it the other way until it taps is again, make a second mark. True TDC will be in the middle of those two marks.

Usually you can simply make a new mark and go with it; however, 30+ degrees is a lot so if this ends up being the problem I would make certain it is not possible to just spin that outside ring - perhaps it is severely warn and the entire damper needs replacing.

I am curious about this "one tooth off" stuff - can somebody please explain? If you set the engine at TDC and the distributor rotor is facing exactly at the #1 contact point on the cap - then timing is 0 degrees. Being a tooth off will simply mean the distributor will sit at a little different position than it would on the original tooth. A tooth off can impact the timing measurment if you have calibrated the rotor position to the crank position since the rotor is mechanically linked to the crank shaft.

The tooth the distributor sits on tends to be more important in a automotive application when there is a vacuum advance because this limits the amount the distributor can be rotated before the advance hits something. Otherwise it is simply a convention that helps us all keep the plug wire connections correct in our heads.

Luv2Ski
07-14-2010, 10:38 AM
Great boat by the way.... it looks just like the 88 I bought last year except for that huge engine... your gona love it.

thatsmrmastercraft
07-14-2010, 11:42 AM
I am curious about this "one tooth off" stuff - can somebody please explain? If you set the engine at TDC and the distributor rotor is facing exactly at the #1 contact point on the cap - then timing is 0 degrees. Being a tooth off will simply mean the distributor will sit at a little different position than it would on the original tooth. A tooth off can impact the timing measurment if you have calibrated the rotor position to the crank position since the rotor is mechanically linked to the crank shaft.


If the distributor isn't properly indexed to the timing marks on the harmonic balancer, the timing marks wrong. If you put the distributor in one tooth off, you would have to know how many teeth are on the distributor gear and calculate to figure out where you would have to set the timing for the engine to be timed properly. Hence Joel's 454 running at 38 degrees at idle.

Luv2Ski
07-14-2010, 12:31 PM
If the distributor isn't properly indexed to the timing marks on the harmonic balancer, the timing marks wrong.

I agree with this statement; however, the indexing is correct if the crank is at TDC and the rotor is pointing at the #1 plug (0 degrees timing). For the tooth off problem to impact timing he would have needed to set the distributor at the location it was at prior to being one tooth off. Since he rotated the distributor until the rotor pointed at #1, being a tooth off will not matter. The only difference will be that the distributor will sit at a different angle that it originally did. Heck, he could be five teeth off and as long as he turned the distributor a bunch and lined up #1; the timing would still be set at zero.

Happy to be shown that I am wrong, but when it comes to setting the distributor one-tooth-off is a bit of a urban legend. I think it stems from being one tooth off with a timing belt or chain; which of course causes very poor performance.

Just did a quick google search, consensus is indeed that it is not possible to be "one tooth off".

thatsmrmastercraft
07-14-2010, 12:50 PM
Happy to be shown that I am wrong, but when it comes to setting the distributor one-tooth-off is a bit of a urban legend. I think it stems from being one tooth off with a timing belt or chain; which of course causes very poor performance.

Just did a quick google search, consensus is indeed that it is not possible to be "one tooth off".

Oh, I didn't realize this was a pi$$ing contest. I was just trying to help another MC enthusiast.

Of course the indexing of the body of the distributor has no effect on a bench motor. In a rare Mastercraft, keeping parts in their original location is important. With that in mind, proper indexing is required.

jconover
07-14-2010, 01:31 PM
Luv2Ski's logic is exactly what I arrived at - However, after searching a few more sites and also talking to the local GM truck shop, I found consensus in one thing I hadn't been doing: Align the 'pin' on the gear with the mark or hole on the distributor before dropping it in, and generally line the rotor up to the distributor cap key (which should be right before cyl #1).

Got the new mallory this AM, so as soon as I can get out of work, i'm going to go and drop it in and check the timing.

Luv2Ski
07-14-2010, 02:41 PM
Not a contest, just a friendly debate - the tone of my responses is not intended to offed, please don't read them that way. I too am trying to help jconover and future readers by ensuring they have accurate information to quickly and easy diagnose the problem.

This is very interesting to me. For what it is worth, with the 454 in my Chevelle I could definitely compensate timing within a tooth with no issues. I did this on purpose when I installed a MSD ignition system so that I could put the vacume advance in a particular location to avoid pinching some electrical cables. The marinized engine is not much different.

Curious to hear how it goes with the new distributor, I put the Mallory in my 351w earlier this year and have nothing but good things to say.

JLeuck64
07-14-2010, 03:11 PM
I am curious about this "one tooth off" stuff - can somebody please explain? If you set the engine at TDC and the distributor rotor is facing exactly at the #1 contact point on the cap - then timing is 0 degrees. Being a tooth off will simply mean the distributor will sit at a little different position than it would on the original tooth. A tooth off can impact the timing measurment if you have calibrated the rotor position to the crank position since the rotor is mechanically linked to the crank shaft.

The tooth the distributor sits on tends to be more important in a automotive application when there is a vacuum advance because this limits the amount the distributor can be rotated before the advance hits something. Otherwise it is simply a convention that helps us all keep the plug wire connections correct in our heads.

Yup, your logic is spot on... being a tooth off, so to speak, is not a huge deal on V-8's cuz the firing impulses are so close together. It tends to become more of an issue when working with some six cylinder engines and more so with 4 cylinder engines because the firing impulses are farther apart AND there may not be enough adjustment available on the distributor housing...

jconover
07-14-2010, 04:51 PM
Thanks guys - I will post the results when I get it together. To the earlier post about the balancer having slipped - I verified that the balancer was exactly in sync with the timing marks when I had the heads off. I am 100% certain that the balancer has not slipped on its rubber housing, so I can safely rule that out of the equation.

jconover
07-16-2010, 03:42 AM
Had planned to start installing the distributor tonight, but got sidetracked. Pulled the wiring harness and main feed out of the boat and started the job of repairing/restoring them to their original function. The previous owner had bypassed all the safety interlocks, and had run an extension cord from the starter solenoid to a momentary contact switch on the dash. Mind you, it worked... but something about jogging a switch to start the motor seemed a bit too redneck to me. Turns out he had a bunch of splices in the wiring harness; I soldered them all together and put heatshrink tubing over the resulting joints.

Finished rewiring the ignition circuits; new ballast resister, installed coil. waiting for fedex to show up in the morning with my new battery to starter cable; the existing one only had about half of its strands in the connector, and it was clearly picked up from some local automotive store (not marine quality wire, and it shows)

Can't get the engine back to top dead center to install the distributor until i get the starter back in (I replaced it with a high torque starter. Hoping to cut down on battery drain -- the boat did not charge the battery fast enough to keep it from running down on earlier trips)

STRIPPED A BOLT ON THE STARTER. Rats. Do you guys recommend tapping to a larger size (would be a 1/2 inch bolt), or using a helicoil to repair the 7/16" thread that was in there? Any experience out there would be appreciated.

jconover
07-16-2010, 03:49 AM
Oh yeah. Blower motor. Non-existant. Found the leads lying in the bilge when I pulled the wiring harness. That explains why I couldnt find it.

Can someone please describe in detail how a blower motor is installed? Which way does it blow? Where does the hose run to? I have air intakes on the front, and i'm guessing there is an exhaust up behind the gas tank (haven't gotten to that end of the boat yet). Dealer told me i should find the blower motor right in the engine box... but where does it install? Near the driver's seat? passengers'? i'm guessing it is closer to the front of the boat because the leads weren't long enough to reach behind the motor.

Thanks

TLR67
07-16-2010, 08:52 AM
Oh yeah. Blower motor. Non-existant. Found the leads lying in the bilge when I pulled the wiring harness. That explains why I couldnt find it.

Can someone please describe in detail how a blower motor is installed? Which way does it blow? Where does the hose run to? I have air intakes on the front, and i'm guessing there is an exhaust up behind the gas tank (haven't gotten to that end of the boat yet). Dealer told me i should find the blower motor right in the engine box... but where does it install? Near the driver's seat? passengers'? i'm guessing it is closer to the front of the boat because the leads weren't long enough to reach behind the motor.

ThanksBlower Motor should Mount on the Drivers rear side of the engine with a open hose Facing forward and exit hose connected to vents in back... Hope that helps..
Intakes in front should run under the bow and in the floor before battery box...

TLR67
07-16-2010, 08:54 AM
Helicoil and Loctite for that Starter Bolt

thatsmrmastercraft
07-16-2010, 08:59 AM
Can't get the engine back to top dead center to install the distributor until i get the starter back in (I replaced it with a high torque starter. Hoping to cut down on battery drain -- the boat did not charge the battery fast enough to keep it from running down on earlier trips)
.

Use a long 1/2" drive ratchet with a deep socket on the end of the crankshaft to turn the engine over. Using the starter will not give you the precise control to make this job simple.

jconover
07-16-2010, 03:25 PM
Wish I could - the raw water pump is on the end of the driveshaft. FWIW I use a strap wrench to do the precise alignment; I just use the ignition to get me in the vicinity.

jconover
07-17-2010, 03:03 AM
OK so i was able to turn the engine over using a 12 point socket on the water pump spline. Not sure that is a good idea, but i only needed to go an inch or so.

New Mallory distributor is installed; i ended up aligning the pin/screw in the spline to the hole in the mallory distributor, adjusting the oil pump slot to match up, and chose a spline/tooth alignment that resulted in plug #1 pointing approximately at cylinder #1. I agree that there is no such thing as 'being off a tooth' unless you are trying to re-install a distributor to a set of marks that you made when you took it out.

After a bit of troubleshooting electrical (note below) - the engine fired right up. it was about 16 degrees before top dead center. not bad for eyeballing it. After coming up to temperature, I adjusted the timing to 10 degrees BTDC, though the engine idled much nicer at 16 degrees. I think i'm going to need to fiddle with the idle loop on the carb next; i dont even know where it is set right now, but i'm guessing that now that i'm somewhere in the right neighborhood of timing, i need to bottom out the idle screws and then back them out 1.5 turns and go from there. Hopefully i can get her to purr tomorrow.

The new starter motor is awesome compared to the old one. Turns the engine with ease, and I don't get any back-rotation when cranking. I did clean up all the electrical too, which I am sure helped, but that new starter does more work with less energy.

Question on electronic ignition/electrical - the factory wiring had an additional lead coming from the "I" terminal of the starter to the positive terminal of the coil (bypassing the ballast resistor). Vince at skidim said that this was to provide extra 'hot' to the coil when cranking, to facilitate a better start. But when I tried to start the engine that way, i lost all spark. I unwired that extra wire, and it fired right up. It may have been something else (I didnt have any spark plugs connected when I tested this... could that be the problem?) Going to reconnect it tomorrow after I put a meter on it to make sure it is only delivering voltage while cranking.

Luv2Ski
07-17-2010, 01:29 PM
Sounds like you are on road to a smooth running engine now. In terms of the idle comment, when you were running more advance you were probably at a little higher rpm which will start moving from the carb idle circuit to the primary jets - correcting the air/fuel mixture. Hopefully once you get your idle circuit tuned it will run smooth. 1.5 turns is a good starting place, but while you are at it be sure the engine dies when you turn them all the way in - that way you know the power valve is good - impossible to tune idle if it is bad.

Vice is correct about that extra wire, it does indeed just deliver full current during starting. This is primarily because the starter is drawing down the voltage already, bypassing the resistor ensures a good spark. I think it is usually hooked up to the output side of ballast resistor, rather than directly to the coil, but the result would be the same either way. Your test sounds like a good idea to ensure the connection to the starter is correct and that there is not a short circuit somewhere. If the engine starts good without it, might not even worry about having that wire in there; particularly since your new starter is probably more efficient that the stock unit.

jconover
07-18-2010, 04:12 AM
Tonight's progress: Started adjusting the idle circuit. The idle screws were only about 3/4 turn from being bottomed out. I reset them to 1.5 turns out, and was able to dial the timing at at 10 degree BTDC and 740 rpm in neutral. She drops to about 600 in gear. Power out of the hole is great. Since I'm still under the two-hour break in period, I didnt take the engine over 3000 rpm, so I haven't been able to check on the secondaries yet (no fuel coming into them at ~2800 rpm). All in all, seems to be running great. She is cold blooded at the dock, however - i needed to give it gas to keep it running until it got to about 120 degrees. I may need to adjust the choke a bit, but I think this engine may just need a little more gas when she is cold.

I seem to have a vacuum leak somewhere - I put a vacuum meter on the end of the PCV hose and it was dancing all over the place between 5 and 10 inches Hg. Dancing so fast i couldnt really tell where it was. I did find a leak on a port on the carb - right next to the choke, there is a strong vacuum on that port. Putting my finger over it doesn't seem to have any major impact on idle performance, however. Plugged the leak, but I haven't checked vacuum again yet. got busy with other stuff.

Question for you carb geniuses out there. Everyone says to set the engine at 1000 rpm and then adjust the idle mixture, turning the needle further and further out until you hear the rpm decrease. I can take those screws out to 4 turns and i don't hear any difference in RPMs, positive or negative. Is 1.5 turns out perhaps too far? If I turn them more than 3/4 turn in, the engine is about ready to die.

JohnnyB
07-18-2010, 09:13 PM
Are you doing all your adjusting on the river????

They do make something called a "fake-a-lake" that connects to your garden hose and fits over the raw water intake to the engine so you can run your boat in your driveway.

jconover
07-19-2010, 02:20 AM
LOL no - I built my own adapter hose for the raw water intake. I've tested on the water twice - once because was expecting to measure the timing advance at 3000 rpm (which I could have done in my yard, but i'll take any excuse to get on the river) - and the second time to measure the RPM drop when I put the boat in gear --- keep in mind, when I got it, it dropped 500 rpm and pretty much stalled if you didnt give it gas ASAP after putting it in gear. It's dropping about 150-200 now, if that.

Luv2Ski
07-19-2010, 10:12 AM
She is cold blooded at the dock, however - i needed to give it gas to keep it running until it got to about 120 degrees. I may need to adjust the choke a bit, but I think this engine may just need a little more gas when she is cold.

This is not unusual for a carb boat because the choke is not designed to put the engine into a high idle when it is cold (throttle linkage does not permit this). Might improve though as you work your way toward a tuned boat but a lot of people have to warm up their engine on the trailer for a minute.


I put a vacuum meter on the end of the PCV hose and it was dancing all over the place between 5 and 10 inches Hg.

You probably want to use a "T" so the PCV is still attached. By plugging that line you are changing the amount of air that is entering the engine which will mess you up if tuning based on vacuum. I agree, continue looking for leaks; particularly since your readings are low. Bouncing vacuum can indicate an intake leak near one of the valve ports, perhaps one of your gaskets did not seal when you reassembled. Can try the old carb cleaner trick to locate. Bouncing vacuum can also indicate more serious problems... but lets not go there.


Question for you carb geniuses out there. Everyone says to set the engine at 1000 rpm and then adjust the idle mixture, turning the needle further and further out until you hear the rpm decrease. I can take those screws out to 4 turns and i don't hear any difference in RPMs, positive or negative. Is 1.5 turns out perhaps too far? If I turn them more than 3/4 turn in, the engine is about ready to die.

Definitely not a genius so hopefully somebody else can chime in as well. A 454 can consume a lot of fuel at idle, so I perhaps with that 4160 in its current configuration, you simply can't put it into a rich enough condition to slow the idle with the screws alone. When you get it to the water, try running the screws rich, let it idle for 30 seconds or so, then try to accelerate quickly. If the engine bogs down, you were running rich.

The other possibility is that your carb has some gunk buildup that is limiting the amount of fuel flowing through the idle circuit so that the screws stop having an impact. If this is the case, only fix is probably a carb rebuild ($26 and about 3hrs).

In any case, if the engine is idling well and your hole-shot is good, with the screws set where you have them you might not bother worrying about it for now - move onto the next project or enjoy....

jconover
07-29-2010, 12:08 PM
Hauled the boat up to michigan and installed the perfectpass on the water over the weekend. That was the easiest thing i've done in this boat.

A great weekend was had by all. Burned 50 gallons of gas over about 10 hours of skiing, footing attempts, and wakeboarding.

Footing attempts here (welcome comments and suggestions): http://mastercraft.com/teamtalk/showthread.php?t=221&page=48

Here's one video of a buddy wakeboarding - you can hear the engine sound pretty well on this vid.
http://www.youtube.com/watch?v=6pfjHcJBvhQ

Speaking of engine sound -- this boat is loud - especially behind the engine box. Not deafening, but you cannot have a conversation between the front seat and the rear seat when the boat is on plane. Not sure if I really WANT to quiet it down -- it is a 454 afterall -- but interested in whether anyone has had any real success in quieting down a noisy boat. Any idea if there is any muffling in this exhaust train right now? Best I can tell, the exhaust pipes exit directly out the rear of the boat. I don't *see* a muffler, but I may not know what to look for.

jconover
07-29-2010, 12:35 PM
Engine operating pics:

At Idle: http://www.youtube.com/watch?v=xqEaCF-qtJI
At 3000 RPM: http://www.youtube.com/watch?v=yQ5gvapOH6A&feature=channel

(second video includes some nice pics of the wake and the exhaust, briefly)

Craig
07-29-2010, 01:08 PM
Speaking of engine sound -- this boat is loud - especially behind the engine box. Not deafening, but you cannot have a conversation between the front seat and the rear seat when the boat is on plane. Not sure if I really WANT to quiet it down -- it is a 454 afterall -- but interested in whether anyone has had any real success in quieting down a noisy boat. Any idea if there is any muffling in this exhaust train right now? Best I can tell, the exhaust pipes exit directly out the rear of the boat. I don't *see* a muffler, but I may not know what to look for.

One thing you can do is replace the insulation in the engine box. I have some pictures of my install here:

http://www.mastercraft.com/teamtalk/showpost.php?p=681624&postcount=71

It has helped quiet our boat down a bit. If you have little to no insulation on your box it will help a lot.

It looks like you had some mufflers in the video, the yellowish fiberglass tubes in the exhaust lines. Maybe they are just PVC or something though, not sure.

jconover
08-02-2010, 12:02 PM
Had a pretty poor weekend. Apparently 2 tanks of fuel through the new engine was enough to suck some crud into my carb -- engine idle went from purr to stumbling idle below 1100 rpm. Double checked the timing and everything else seemed fine, so I pulled the carb last night. Got lots of bits of debris when i pulled the fuel lines from the carb, and more when I drained the bowls. Pulling the bowls off revealed a few corroded bowl screws, and the welds/brazing on the primary float showed the telltale green and white discoloration of water in the fuel system.

Also, at idle, noticed that i was only getting good spray down the throat of the port side primary bore in the carb. I am assuming I should be seeing good spray in both primary bores at idle???

Ordered up a water separating fuel filter, new fuel line, and a carb renew kit. Started soaking the primary metering block last night in carb dip. The main carb body is too big to fit in my dip jar -- not sure what i'm going to do about that.

Extra information for the record. After talking to Indmar and Holley, I can share the following info about the 454HO.

Factory carb was a 4150, later replaced by the 4160. The carb is an Indmar OEM part number (75032), meaning that the exact details of the carb and jetting are proprietary - holley techs don't get a parts explosion, because the carb was custom configured and packaged for indmar. Despite the fact it is not produced anymore, they can't give me much info. Here's what I know about this exact carb:

It is a Holley 4160 body, 750 CFM, with dual fuel inlets and a vacuum activated secondary (this is standard for marine carbs). The main jets in this model were #76, and the secondary has fixed jets, rather than a metering block. The secondary jet equivalents are 79 thousands. The Indmar rebuild kit for this carb is (EDITED:) NOT Indmar part #S611021. (I got the kit and started rebuilding only to discover the S611021 is for a 600 CFM carb... S611021 is just a Holley 703-47 FYI)

This carb is basically the same as the Holley universal marine calibrated 750 CFM 4160, model 0-9015-1. The 0-9015-1 has basically the same characteristics -- primary metering block, secondary plate, same jetting. You can order a secondary metering block from holly for the 0-9015-1 - (Sales #34-13) i dont see any real reason to order the block, other than it would be another set of needles to adjust and another piece i'd need to dip. The metering plate actually cleans up very easily, since you can see all the passages when you pull the plate off (they are mated to a gasket rather than being enclosed in a block of metal). (EDIT: rebuild kit for a 0-9015-1 750 CFM carb is 3-720)

The primary float in the carb i've got is a hollow brazed brass float. The secondary is a niphenol. I spoke to holley, and this is how they ship them from the factory. I am going to replace the primary float with a niphenol float, since the brazing on the brass is showing a lot of corrosion.

My carb has a 10.5" Hg power-valve in it. This may explain why my idle circuit has very little impact on the idle of the engine. Turning the needles all the way in does snub the engine, but basically once you get the needles turned out a turn or so, there is no noticable difference in engine idle no matter how far out you turn them. I will update this post with the OEM power valve info when the renew kit shows up later this week

jconover
08-02-2010, 12:07 PM
Also finished my welding project this weekend. Converted traditional bar-style MC trailer to boat-buddy enabled trailer, and moved the winch up onto an arm on the stanchion to provide straighter winch pulling capability. Will snap some photos when I get back from work. Works nice.

Boat buddy question: The boat buddy locking mechanism worked perfectly when i ran the boat up on the trailer, locking the boat in place nicely. However, when I pulled the boat out of the water, the boat was pulling on the pin of the boat buddy, and it settled back on the trailer a bit. As a result, there was about a 1" gap between the bow of the boat and the v-shaped bunk at the front of the trailer. I backed it into the water and float the boat forward on the trailer using the winch to pull it forward, and it all settled in just fine.

Do other people have this issue? Do you latch the winch rope and tighten before pulling the trailer out of the water at the launch?

Also, after doing this procedure, the boat was no longer pushing on the boat buddy release, meaning i couldn't fully release the boat buddy pin without reaching my fingers up under the boat buddy and pushing on the release mechanism so that I could fully extract the pin. Am I missing something here?

Luv2Ski
08-02-2010, 12:45 PM
Had a pretty poor weekend. Apparently 2 tanks of fuel through the new engine was enough to suck some crud into my carb

Have you checked to be sure the two stock filters were in place? If it is like the 351, there is an aluminum water separator mounted near the forward engine mount with a filter in it and a second filter in the fuel pump itself.


Also, at idle, noticed that i was only getting good spray down the throat of the port side primary bore in the carb. I am assuming I should be seeing good spray in both primary bores at idle???

Yep, should be coming from both indeed. Hopefully the rebuild will fix that up for you.


My carb has a 10.5" Hg power-valve in it. This may explain why my idle circuit has very little impact on the idle of the engine. Turning the needles all the way in does snub the engine, but basically once you get the needles turned out a turn or so, there is no noticable difference in engine idle no matter how far out you turn them. I will update this post with the OEM power valve info when the renew kit shows up later this week

Wow, that would cause a very early enrichment. Don't expect your rebuild kit to come with the exact factory one. The marine rebuild kit specified by holley for my 4160 came with a 5.5 instead of a 2.5.

454Prostar190
08-02-2010, 01:32 PM
Engine operating pics:

At Idle: http://www.youtube.com/watch?v=xqEaCF-qtJI
At 3000 RPM: http://www.youtube.com/watch?v=yQ5gvapOH6A&feature=channel

(second video includes some nice pics of the wake and the exhaust, briefly)

jconover,

This sounds real close to the 454 in my boat. I can't get her to idle below 900rpm. Is that what I heard you say in the video? And yes, very loud! Rick

jconover
08-02-2010, 01:40 PM
Yeah - 900 at idle, 650ish in gear. Actually got it dialed down to 840 RPM last week. Manual says 600-650 in gear, so we were on the money... just couldn't make it last for more than a week. I'll keep posting in my diary here as I work to improve it.

What do you run your timing at? Do you have a stock cam? My engine has a lope -- i didn't measure the cam lift when I had the heads off... wish I had - but PO told me the engine had a custom CAM; probably close to 500HP.

RE: Filters above -- this is funny - the secondary had a composite filter (looks like a fish tank aereator). The primary had no filter, screen or otherwise. I ordered a new set of filters from Summit Racing ($11 ea with springs and gaskets) today. PO had wired in a fram fuel line filter just below the fuel pump. I am replacing that with a water separating filter tonight. I don't think it can hurt to have the extra filters up in the carb body.... though if something did get in there, it would be a pain to diagnose.

454Prostar190
08-02-2010, 01:58 PM
No, not a stock cam in mine. I don't know what it is but, it has that bit of chop, like yours at idle. I do know that I have the high performance 990 rectangular port heads.

jconover
08-02-2010, 02:15 PM
Yeah the square manifold openings are the difference between the 375 HP standard and the 425 HP HO model.

Following up on my previous post - the stock power valve in the Indmar OEM rebuild kit for the HO engine is the 5.0 (inches of mercury) powervalve. Posting for others' future reference

jconover
08-05-2010, 11:31 AM
Grumble Grumble. Dug in to my carb last night after getting the supposed carb rebuild kit from Indmar. That was a $77 mistake (+$16 s/h). The Holley 703-47 (Indmar #S611021) which Indmar told me was correct for this carb... was not.

I am now ordering a stock 3-720 750CFM Holly 4160 rebuild kit hoping I get the correct base gasket and metering plate gasket. $32 at napa and it will be here tomorrow.

This also calls into question what size the power valve is.

454Prostar190
08-05-2010, 12:21 PM
A good speed shop should be able to provide what you need with the numbers on the existing carb, including the power valve. Make sure that you specify 'marine'.

jconover
08-05-2010, 01:06 PM
The carb is a prorietary OEM part number; even half the techs at Holley can't seem to find it (I found one guy there that "knew the system" well enough to reference it out - but the file on the carb is sealed, meaning he can't get the parts explosion.

That said, i'm sure I can find a power shop once I get the damned thing back together. General rule of thumb for a car is your PV should have a value equal to half your intake manifold vacuum at idle. Apparently boats open up a lot later, since it seems most use a 2.5.

What I do know is this: The boat actually ran really well with the 10.5 that was in there. Of course, I don't have another 454/PS190 to compare performance to.. maybe it accelerated like crap and had all sorts of flat spots :-P It was so much more powerful and responsive than my previous boat, I'd never really know it. But then again, I don't think that is the case - this thing pushed you back in the seat when you put the hammer down.. and planed out in about 3 seconds. It pulled me (220lb) up instantaneously. I dont think it was having performance problems in the mid to high end... just idle sucked.

I'll get the holley 4160/750CFM kit tomorrow and finish putting the beast back together. crossing my fingers that everything is peachy at that point. Somehow, I think i'm going to be a bit disappointed.

jconover
08-09-2010, 12:42 AM
Okay...

Carb is rebuilt. Looking for good tuning advice Now. Here is where I am at:
Reminder: this is a 425+ hp 454HO with what is most likely custom cam
1. Engine runs great at idle. Can dial it to 700rpm no load, 600 rpm at load
2. Engine had a small amount of hesitation on acceleration. I advanced the timing to 12 degrees btdc based on recommendations from a local performance shop... This helped me get the idle dialed in, starts better, and hesitation is gone.
3. The marine rebuild kit had a 8.5 power valve. Prior to rebuild was running a 10.5. Power valve is known good. Floats are set correctly. Engine will get weak but will NOT die if I turn the idle needles in all the way.... Any ideas where it is getting fuel?
4. Have had two backfires when putting the throttle fully down from idle. (rechecked pv, did not turn freely). Idle screws are set 1 turn out, or so. No amount of idle adjustment sounds better than here, in my minds ear anyways.... Thoughts?
5. Idle vacuum is solid at 12-15
6. Top end is awesome. 4600 rpm 46 mph....could go higher on the throttle but that is redline for this engine.

Really want to know where that backfire is coming from and why it idles with the needles bottomed out. Hoping there is some good sage out there.

Luv2Ski
08-09-2010, 09:32 AM
My guess would be too much fuel just above idle causing both that sneeze and the hesitation. Does it do this while in neutral or when in gear, or both?

A 8.5 PV is still pretty high for marine application, particularly if your idle vacuum is ~13. I have had these same symptoms on a ground-based 454 and was able to take care of them with PV adjustments. For what it is worth, that was a built engine with a cam as well and I ended up running a 6.5, if memory serves vacuum was a little lower than yours though. I would try a 4.5, possibly even go down to the 2.5. Wish somebody could tell you what the stock PV was.

Did you check that the new and old carb have the same primary jets (that said, you don't really know if it ran good with the old setup to you?).

I have found the holley tech hotline to pretty good about pointing me in the correct direction. You might give that a try as well.

1redTA
08-09-2010, 10:57 AM
A performane engine won't use the same size power valve as a high po engine

jconover
08-09-2010, 04:31 PM
Luv2Ski - thanks for the nudge in the right direction.

It is my best guess that the original carb on the engine was a Holly 4150, but your guess is as good as mine on what the original power valve was supposed to be. I am not looking forward to pulling the primary bowl off - draining fuel over and over is a pain in the butt, but I have a 6.5 PV sitting here from the automotive kit, and fortunately my local O'Reilly's has a great selection of power valves hanging on the wall in their performance section. I have several 2.5 PV's lying around.

But to close the thought, you think the power valve could be causing the "sneeze"? (good term!) I've only had it happen twice. Here's when:

Tuned boat idle... goosed throttle many times to test for hesitation/response. Did this on dry land. Got one pop on goosing, not after any particularly long amount of idle.

Second sneeze came while out on the water with the kids. Had been running WFO down the river, came up to some heavy boat traffic, so I dropped down to idle (not neutral, just in gear). idled around for about 2 minutes, turned the boat back downriver, and when I went to give it, she sneezed. I let off and then goosed it a few more times (kids like the sudden acceleration) -- didn't get any more sneezes.

so to answer your question, the sneezes came when in gear, or when it would have been in gear (neutral lockout used on land, of course)

454Prostar190
08-09-2010, 05:24 PM
My 454 doesn't like low rpms and with the large rectangular port heads, will load up a bit at an idle or just off idle. No "sneezing" but, if I'm in a long 5 mph zone, I'll have to take her out of gear, give her a couple of revs, to clear the ports, and then back in gear. Another thing is that I can't get her to idle lower than 900. I've tried, and she'll run, but the moment I engage the prop, she'll load up and die. With a 900rpm idle, she just runs and will run up to 5500 without a problem.

jconover
08-09-2010, 05:58 PM
Hmm - interesting - if you try to give it after the long idle, what happens? Does it just die?

Regarding idle speed, I got it dialed down pretty good with the recently rebuilt heads (all new valves) and the newly renewed carb. I got it to idle at 600, but the in-gear reduction to 450-ish was a bit much for that motor. Actually was able to keep it there once she is hot, but I want clean operation when cold, too - so i decided to idle at 800 and in-gear at 650. Actual idle right now jumps between 740 and 800 on the perfectpass.

Do you happen to know which power valve you run?

You run that engine up to 5500 RPM? All the books i've read indicate top RPM is 4400-4600. I think i might break the sound barrier if I pushed the engine to 5500 rpm. :):) I'm pushing 46 mph at 4600 rpm, can't see why i'd want to run much faster than that, other than for thrills.

Luv2Ski
08-09-2010, 06:03 PM
You may do this already, but one thing I do to cut down on the fuel spilling is to hold a small container (like the top of a spray paint can) under one of the lower bowl screws, pull out that screw and then wait for the bowl to empty. I hear some people disconnect the fuel line at the pump and then start the engine to run it dry, but I have never tried that method.

I prefer the term sneeze too; it helps alleviate the confusion with a exhaust backfire. It is a pretty common term with the muscle car guys, holley calls it a sneeze in some of the literature as well.

I continue to suspect the PV, at least it is a good place to start.

Not sure if you have thought about this but here is my understanding. In a car the engine is not loaded immediately off idle. Rather the RPMs are a bit higher because the driver is either revving the engine while engaging the clutch or the torque converter is slipping. The result is that vacuum curve does not drop off as steep as it will in a boat where the engine is loaded essentially right off idle. This is why boats tend to have a PV that opens later (at a lower vacuum).

The second sneeze sounds like a good example of when a rich low circuit would cause a sneeze. Not really related to the amount of time idling but rather the acceleration under a certain load.

For kicks, you might start with that 2.5. It seams to be such a standard among marine engines in general that you may have good results with it. Then again, since your sneeze is inconsistent, perhaps the 6.5 is a better place to start.

Also, just got to thinking about how you can't kill the engine with the idle screws turned in. Did you check the needles at the end of the screws to be sure they are in good shape?

jconover
08-09-2010, 06:31 PM
So I called holley based on the earlier recommendation - their tech line is really great by the way (I've called it several times). I'm going to document this for other future learners/readers:

Your power valve, when it sits on the table in front of you, is open. The vacuum pressure of the engine keeps it closed. (For some reason, I had this backwards in my head).

The purpose of the power valve is to provide additional fuel when the carb moves out of the idle circuit. As you increase throttle, the throttle plate opens up, and naturally, vacuum in the engine quickly drops of to low values.

Now - a power valve rating determines at what vacuum the PV is FULLY open. It will begin to open at some value slightly more than double the PV rating. So for example, a 2.5 power valve will start to open somewhere just above 5 inches of vacuum.

Now my "not in gear" idle vaccum is right around 13 inches of mercury. What I found out from Holley is that you want your power valve to have a value JUST LESS THAN HALF of your "in gear" idle... I don't have that bit of information right now, so I'll have to take the boat out on the water and measure my in-gear vacuum. I'm guessing it is around 10-11 inches. Let's just assume 10 inches for the purpose of this example. Based on Holley's recommendation, I'd want to use a power valve with a rating less than 5... 4.0 or 4.5 for example.

My boat is likely loading up on extra fuel at idle because the power valve is partially open at idle. Thus, when I put the hammer down, I am in an over-rich condition, and I get a backfire through the carb. Also, this partially open condition is what is causing my boat to not 'die' when I turn the idle screws all the way in... a little bit of fuel is trickling through the power valve, feeding the engine gas even with the idle circuit closed.

I am going to measure my vacuum and then try an appropriate power valve. I will continue to post results based on my measurements and attempts. I have a 2.5 lying around, I could just try that too... but I think i'll take the time to measure the vacuum and determine the right value.

For kicks - I also asked what effect a "too small" power valve would have on the engine -- generally, he said the net result is a stall/heavy hesitation on opening up the throttle... he described it as a "cough". Sneezing, coughing... geez :)

Regarding draining the carb -- that's exactly what I do -- top of a spray paint can works well, though it is a tight fight based on how I have my fuel line mounted. (Did you watch the same youtube videos as I did?)

Luv2Ski - what do you mean about the 'second sneeze' below - are you saying my idle valves may be a bit too rich? I will have to completely retune after I change out the power valve anyways, since clearly that was an additional source of enrichment in the engine.

Luv2Ski
08-10-2010, 07:55 PM
Nicely summarized.

One thing the guy I talked to a while back on the holley line told me, was that the 1/2 vacuum in-gear rule applied primarily to cars. He said that boat manufacturers often select a PV that opens later (lower number) because the engine is always loaded. That was his excuse for why the rebuild kit they recommended for my carb had a 5.5 PV instead of a 2.5 PV (which confuses me a little since it was a marine kit, but what the heck).

When mentioning the second sneeze, I was concerned that your rich condition may have been from something other than the PV since it occurred with no load. I suspect decreasing the PV will solve the issue completely (and heck, probably save you some fuel too-always appreciated with a big block!).

Not sure how you tune your idle screws as there are a number of methods. I can give you some tips on how I do it if that would be helpful.

Best of luck

jconover
08-10-2010, 11:07 PM
I would love some tips - I'm not very good at it :-)

jconover
08-12-2010, 06:15 PM
Shots of some of the repairs done this week. I ended up painting the repairs,and the match came out a bit light. However, good buffing also seems to bring the gelcoat finish up a bit lighter, so I think i am in okay waters there.

Luv2Ski
08-13-2010, 09:22 AM
I know pictures can be deceiving as I can't see any differences in color, it looks fantastic.

As for idle screw adjustment, have you tried setting them using the vacuum method? While a lot of other methods require a little hand waiving, this one lets us trust in a gauge and has worked well for me more often than not. In essence, you are simply adjusting the screws to obtain maximum vacuum at a specific idle speed.


Note the current location of both screws, I recommend you start with them both in the same location, probably ~1.5 turns out.
Hook up your vacuum gauge ("T" into the PCV line, don't unhook the PCV as it impacts the mixture)
Hook up a low RMP gauge (most dwell meters have this built in). You can get around this using the tach, it is just a tad less sensitive.
Warm up engine to operating temperature
Set idle speed
Turn first screw in, 1/4 to 1/2 turn
Re-adjust idle speed
Compare vacuum to previous value, if increased turn other screw in same direction and the same amount
Re-adjust idle speed
Compare vacuum to previous value.
Continue making adjustments until the vacuum decreases, then you have gone too lean, put the last screw back.
Check other screw case it needs more adjustment.
That should be it


Of course, if your first adjustment results in a decrease in vacuum, you were on the lean side to start with so simply follow the same process but turn the screws in the opposite direction.

While adjusting the screws you can start to foul the cylinders and that messes up the entire tuning process. The result is that after running the boat at speed, the idle will behave different than the one you tuned. When I think I am getting close, I like to run the engine at cruising speed, even a bit of WOT, for 5 to 10 minutes, then do the final tuning.

After you are finished and assuming you don't have a flat spot off idle, the ultimate test is a extended idle cruise, you know, the "site seeing type". If you can idle around in gear for 15 minutes and then hit the throttle without any hesitation, you have the perfect adjustment.

I also like to do everything while in gear. I think you can do a pretty good job in neutral as well, I just figure the engine spends more time idling in gear than out of gear so I tune it in that state.

Sorry for the delay, I was actually out on the lake for the last couple of days.

jconover
08-13-2010, 09:45 AM
Hey thanks. I'll give it a try.

I did get back out on the water this week - we skied all night with no problems or backfires, so I may just sit on it like it is for a while. I did measure the vacuum at idle, and it is actually only about 5.5 inches in gear... apparently my old measurements were at a lower idle speed (i have written notes showing 11-13 inches earlier). I still may try dropping in a 2.5 power valve and just see where that puts me... sometimes it's hard to know when to quit :-)

I also ran myself out of gas the other night, having too much fun. Turns out my sending unit is calibrated such that 1/4 on the gauge = empty tank. Chris Van Zeeland was nice enough to drag me back to the dock (thanks again, Chris!!). MC towing MC. -=-=sigh=-=- At least it was just out of gas.

DooSPX
08-13-2010, 09:59 AM
Do not feel bad about getting towed in by another MC.

I got towed in by a friends Moomba Outback after a day on the lake when my kill switch bit the dust. To make matters worse, some girls that were younger cousins of theirs saw it and took pictures then posted them on facebook. :mad::rolleyes:

Luv2Ski
08-13-2010, 10:20 AM
I hear you both, last night I had to be towed in by a pontoon boat! Burned up a second solenoid in one week, looks like I have to find a root cause....

5.5 is pretty low if that is at the ~750 rpm idle you mentioned in an earlier post. You must have a sizable cam.... I too would toss that 2.5 in there, but I definitely don't know when to quit :).

jconover
08-13-2010, 10:20 AM
Ahahahahah! priceless. My buddy took several pictures of us being towed (from the passenger seat). He then noticed that our boat had one major deficiency - my boat didn't come with any females. I'm going to have to contact the dealership about that. My other buddy commented that at least we didn't have to deal with the embarrassment of explaining to them that we ran out of gas. :-P

jconover
08-13-2010, 10:27 AM
I hear you both, last night I had to be towed in by a pontoon boat! Burned up a second solenoid in one week, looks like I have to find a root cause....

5.5 is pretty low if that is at the ~750 rpm idle you mentioned in an earlier post. You must have a sizable cam.... I too would toss that 2.5 in there, but I definitely don't know when to quit :).

I'm starting to second guess a lot now. So, last night I spoke to the original owners of this boat. I now know a lot more about its history. It has been locally owned since it came from the factory. The local ski team owned it until 1995 when it was paid off. It had a rebuild at 500 hours on the clock, and all regular maintenance up to that point.

It was sold off in '95 and spent some time in solitary [Eagle River], before making its way back down to my neck of the woods. Was sold many times then, in short order. Some owners had it painted, reupholstered, and did some horrible things to the engine, including putting an automotive distributor in it. I think the previous owner may have done most of the stupid stuff, but I can't be 100% certain.

One thing I know for sure now - The original owners did not put a cam in it. They told me, however, that it has always had that loping sound. I have to wonder how aggressive a cam indmar put in the engine to begin with. Now, I still don't know for sure what happened between 500 and 900 hours, and it is totally possible, given everything else i've seen, that someone did put a performance cam in the engine, but I'm no longer 100% convinced. (I should have measured the lift and travel when I had the heads off...darnit)

jconover
08-13-2010, 10:30 AM
5.5 is pretty low if that is at the ~750 rpm idle you mentioned in an earlier post. You must have a sizable cam.... I too would toss that 2.5 in there, but I definitely don't know when to quit :).

See my above post too - but yes, that's exactly what my mechanic buddy said - we put it in gear and the vacuum drops substantially. Since I know it's not leaking out the transmission :rolleyes: i have to assume it is in the valve train, thus the aggressive cam.

DooSPX
08-13-2010, 10:38 AM
Im not sure on the GM, and on the BBC but im pretty sure Indmar/PCM but a slightly more aggressive cam over factory ford truck motors.

jconover
08-23-2010, 11:49 AM
Had a less than optimal weekend. After 2.5 inches of rain in 45 minutes on friday night (combined with winds that destroyed the awning on my camper), we got the boat in the water saturday morning ~10:30 ish.

Took my daughter on her first ski run ever on the barefoot bar (victory!!) - will post that later.
It's about 12:30 at this point, and the boat dies as i'm coasting it in to the dock. OK, I think to myself... Start it back up, it fires right up, and then dies. Do this 5 or 6 times. I start thinking back to all the advice on this thread -- all it takes is Air, Fuel, and Spark. (reminder, this is an 88 carb'd 454).

So where did I go wrong? I have a fuel pressure gauge that reads the same old 5/10/5/10/5/10 that it always does (mechanical fuel pump). Re-set the idle needles to 1.5 turns out (just for sanity).... checked the choke,... it's open. Engine temperature is fine ~150ish. Spark... distributor cap tightened up... can't check timing, didn't bring my timing light, but there is no reason that the timing should have moved. Can get the engine to run above 1400 RPM... as soon as I start turning the idle screw back down, she dies. Topped off the oil just for kicks (it was 1/2 quart low, had just changed it last weekend, so that's just settling)

Never got it running again that day. Note that power boats can only operate until 4 PM on this lake, so I've got limited daytime to deal with this.

Next morning... walk down to the dock at 11 AM. Turn the key, boat fires right up. Hook up the tube (yeah yeah) and pull 14 kids around in circles at 20 mph for an hour. Last kid is getting his turn, and I can hear the engine missing at 2500 RPM... with a little "pop" noise (not backfire) coming from the exhaust, maybe 20 times per minute. Boat is running rougher and rougher as i limp it back in to the dock. It's about 12:30 again. I was able to drive it back to the ramp and powerload it back on to the trailer -- but it was not happy - I tried to open it up on the water, and it hesitated and was stuttering all through the power curve. no idea what's going on.

I have skied this thing empty from a full tank the last two weeks, and never had any problems. The only major difference I see this week is A) we're skiing at mid-day in direct sun and B) I bought gas up in the northern part of the state. The local boat shop guys commented they've had a lot of bad gas lately, but if that was the case, then WHY would I be able to run great for an hour or two every morning?

I'm stumped and looking for expert advice.

JohnnyB
08-23-2010, 01:36 PM
Had a less than optimal weekend. After 2.5 inches of rain in 45 minutes on friday night (combined with winds that destroyed the awning on my camper), we got the boat in the water saturday morning ~10:30 ish.

Took my daughter on her first ski run ever on the barefoot bar (victory!!) - will post that later.
It's about 12:30 at this point, and the boat dies as i'm coasting it in to the dock. OK, I think to myself... Start it back up, it fires right up, and then dies. Do this 5 or 6 times. I start thinking back to all the advice on this thread -- all it takes is Air, Fuel, and Spark. (reminder, this is an 88 carb'd 454).

So where did I go wrong? I have a fuel pressure gauge that reads the same old 5/10/5/10/5/10 that it always does (mechanical fuel pump). Re-set the idle needles to 1.5 turns out (just for sanity).... checked the choke,... it's open. Engine temperature is fine ~150ish. Spark... distributor cap tightened up... can't check timing, didn't bring my timing light, but there is no reason that the timing should have moved. Can get the engine to run above 1400 RPM... as soon as I start turning the idle screw back down, she dies. Topped off the oil just for kicks (it was 1/2 quart low, had just changed it last weekend, so that's just settling)

Never got it running again that day. Note that power boats can only operate until 4 PM on this lake, so I've got limited daytime to deal with this.

Next morning... walk down to the dock at 11 AM. Turn the key, boat fires right up. Hook up the tube (yeah yeah) and pull 14 kids around in circles at 20 mph for an hour. Last kid is getting his turn, and I can hear the engine missing at 2500 RPM... with a little "pop" noise (not backfire) coming from the exhaust, maybe 20 times per minute. Boat is running rougher and rougher as i limp it back in to the dock. It's about 12:30 again. I was able to drive it back to the ramp and powerload it back on to the trailer -- but it was not happy - I tried to open it up on the water, and it hesitated and was stuttering all through the power curve. no idea what's going on.

I have skied this thing empty from a full tank the last two weeks, and never had any problems. The only major difference I see this week is A) we're skiing at mid-day in direct sun and B) I bought gas up in the northern part of the state. The local boat shop guys commented they've had a lot of bad gas lately, but if that was the case, then WHY would I be able to run great for an hour or two every morning?

I'm stumped and looking for expert advice.

Guessing with your fuel pressure readings, this is frivelous but did you check simple stuff like filter in the mechanical fuel pump and in-line filter from pump to carburetor? Is there a fuel/water separator? How long has it been since it was changed?

jconover
08-23-2010, 01:41 PM
Not aware of a filter in the mechanical pump... Checked the inline from pump to carb, just replaced it when I rebuilt two weeks ago. Just added water/fuel separating filter in front of fuel pump. Haven't "checked" it but was also just installed 2 weeks ago.

jconover
08-23-2010, 11:54 PM
Isolated the problem tonight between slalom and footing runs. Learned another interesting fact tonight as well.

Missing/poor performance/poor idle is coming from an overheated ignition coil. Now, thing is, I just replaced the coil, distributor, ballast resister, plugs and wires.

We verified this by letting the coil cool down for 5-10 minutes between runs. We used a wet sock applied to the outside of the coil body to accelerate the cooling process (apologies to my wife for the wet socks)

One interesting fact I was not aware of: My coil stays hot and continues to produce heat whenever the keyswitch is in the "RUN" position. We were sitting around listening to the radio trying to wait for the heat to dissipate, when my buddy noticed the coil was still remarkably hot. Switched the key to accessory, and the coil cooled off after 10 minutes or so. We were able to ski the rest of the night without incident after this.

I've seen some threads here on bad new coils. I bought this one from SKIDIM. Going to give them a ring in the morning.

Can someone verify that the coil is indeed energized whenever the keyswitch is in the RUN position? Or more importantly, has anyone seen this type of behavior before?

I'm glad this was an "easy" one - I've spent a lot of time staring in my engine compartment this summer, and i've been really itching to put some hours on the engine SKIING rather than WRENCHING :-)

Boiler_81
08-24-2010, 09:13 AM
Yes, the ignition system is switched on when the key is in run. When in accessory the ignition system is not powered. When not running the engine the key should not be in the run position. If you have a points, they can be burnt by leaving the key on run.

87PS190
10-02-2010, 01:13 PM
Joel, any updates? Is it running fine now?

jconover
10-02-2010, 10:01 PM
Mostly - we're into winter here now, so it's sitting in the garage. I never tracked down the Perfectpass reset problem - i am going to dig into the electrical over the winter and try and isolate it.

Nearly everything has been perfect since i finished the tune up - but I have a small problem that seemed to be related to coil overheating - it always cropped up when running at 14-18 mph. I thought it was the coil, but I'm beginning to think it may be due to my float adjustments - the angle of the boat at that speed is very steep, and i hear it miss fairly regularly when pulling my daughter or a wakeboarder. I bought a high-end coil from Mallory, i'm going to give it a whirl in the spring. I will resume this thread then...

89BigBlock
10-14-2010, 01:21 PM
J~ First off well done so far! My boat is almost identical to yours as I've been going thru the resto projects thru the last few hrs. I'm curious how much vibration your getting from the motor? Depending on rpm my mirror shakes quite a bit at 3400. I've checked the prop and it's fine.

cptskier15
07-20-2012, 05:19 AM
Awesome motor!!