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93ps205
07-28-2005, 08:29 AM
I have a 93 MC with the Ford Indmar 285HP. I changed out the Holley
4010 for the marinized Holley 4160 about two years ago. Other components (Plugs, wires, cap, timing, fuel filter, etc) are up to date and the boat runs great.

However, ever since I installed the 4160, there is an annoying
behavior. After running the boat or pulling a skier, the engine
is shut off. When I re-start the engine, sometimes it starts right
up (40% of the time). Other times (60%) it tries to start, but
doesn't quite make it. Then it requires either a pump of the
throttle or for the throttle to advanced forward and then it
starts right up.

Has anyone else had/solved this problem with the 4160?

jake
07-28-2005, 10:20 AM
Had same behavior with my 4110, friend of a friend who knows carbs added fuel to the idle mixture. Now it starts right up 90% of the time, still not perfect, but much better. After he did this I needed to slow down the idle though.

martini
07-28-2005, 10:45 AM
This is a common problem and is probably caused from fuel boiling past the needle and seat in the carb. when you let it sit for awhile after running it. It's called heat soak. You can always get a spacer that will shield the carb from heating up too much. I have one on my '84 and it works perfect. Just a thought.

east tx skier
07-28-2005, 11:09 AM
That's what my 4010 did, but my 4160 has never done that. I do have the spacer that martini mentioned I believe.

Storm861triple
07-28-2005, 01:58 PM
I agree w/the "richen the A/F ratio" for the idle circuit. It's too lean.

I disagree w/fuel boiling. Boats just don't run that hot, and the "under hood temps" are not that hot either. Not hot enough to boil fuel.

As evidence that A/F ratio is the issue and not boiling, my boat starts and runs perfectly in Park City (7000' elevation). When I go to Lake Powell (3900' elevation), I have to give it a "shot" about 50% of the time to start it even warm. Obvioulsy it doesn't run any warmer at Powell then it does in Park City, but it still behaves differently due to the fact that it runs leaner at lower elevation.

-Tom

87MC Dave
07-28-2005, 05:39 PM
do you have electronic ignition or points? My would do the same thing. I would have to pump the throttle before I turned the ignition. I changed over to electronic and it fires up first shot everytime without pumping the throttle. I also agree with the A/F comment. If it is too lean you won't have enough gas if the intake to get it going.

east tx skier
07-28-2005, 05:41 PM
I think electronic ignition was standard in 1993.

87MC Dave
07-28-2005, 05:45 PM
your right...sorry Thought it was an older boat...

93ps205
07-28-2005, 07:14 PM
It does have electronic igniton.

To clarify, sometimes the time between stopping the boat and
re-starting can be as little as 1 or 2 minutes. Probably
not enough time for the fuel boiling scenario.

I think the carb (4160) has one adjustment screw on each side of the unit
and a separate idle speed screw.
There are no external float adjustments. That said, can someone
give a some simple instructions of how to adjust the carb to
correct the problem (A/F mixture)? I'm not sure what these two
screws control.

Thanks so much for the replies so far!!

BriEOD
07-28-2005, 07:18 PM
I think electronic ignition was standard in 1993.
Well of course you do. You can't mount a 4160 to an Edelbrock Performer 351 Intake Manifold without it. ;)

87MC Dave
07-28-2005, 10:44 PM
I turned mine all the way in and then backed it out 2 full turns...A good range would be 1.5 to 2.5 fulls turns out. Hope that helps you.

east tx skier
07-28-2005, 10:55 PM
Brian, are you talking about electronic ignition or the spacer plate?

If you're talking about the spacer plate, I think I have something else, too, that's about an inch thick between the intake and the carb in addition to the adaptor for the Holley to edelbrock.

PeteS
07-29-2005, 10:41 AM
I turned mine all the way in and then backed it out 2 full turns...A good range would be 1.5 to 2.5 fulls turns out. Hope that helps you.
Dave is correct for an approximation on the idle circuit adjustments. However, to run it richer, would you want those screws closer in or backed out further?

On mine I have a range of about a half turn where the boat runs well, but to increase the amount of fuel in the air/fuel mixture, I'm assuming that the screw needs to be closer to fully seated, or in further. Is that correct, or opposite?

martini
07-29-2005, 12:23 PM
I agree w/the "richen the A/F ratio" for the idle circuit. It's too lean.

I disagree w/fuel boiling. Boats just don't run that hot, and the "under hood temps" are not that hot either. Not hot enough to boil fuel.

As evidence that A/F ratio is the issue and not boiling, my boat starts and runs perfectly in Park City (7000' elevation). When I go to Lake Powell (3900' elevation), I have to give it a "shot" about 50% of the time to start it even warm. Obvioulsy it doesn't run any warmer at Powell then it does in Park City, but it still behaves differently due to the fact that it runs leaner at lower elevation.

-Tom

Fuel boiling can be issue with these boats as it has happened to me. SkiDim sells an updated intake manifold gasket for the 351 that helps to eliminate some hard start issues people have with their boats because of fuel boiling and vapor lock. From their website describing the intake manifold gasket:

"A restrictor (smaller hole) in this gasket reduces the amount of exhaust gas that flows across the manifold thereby heating the manifold which had been causing the carb to boil fuel and caused hard re-starts (vapor locking) and IDLE INCONSISTENCY."

Have you ever touched the carb on your boat after running it all day, they get hot. Especially when they sit after a good solid run. I don't care how cold these things run, if you have exhaust flowing across the intake, under the carb, it is eventually going to heat up, and it won't be warm, it'll be hot.

I didn't use that particular gasket, I bought a .5" composite heat spacer that is between the intake and carb that has worked wonders with this kind of issue.

martini
07-29-2005, 12:24 PM
Out is richer, in is leaner. To adjust, start on one side and turn screw in all the way, it may act like it is going to die so be prepared to quickly turn it back out again. Start turning the screw out again until you have achieved the highest idle, note how many revolutions you are turning it out. Proceed to the other side and repeat. It will generally fall somewhere between 1 full turn out and up to 2 full turns. Once you have achieved the highest possible idle with this adjustment, reduce or adjust your idle back to specs with the idle stop screw, not the mixture screws you just adjusted.

Storm861triple
07-29-2005, 03:38 PM
Well, I've never had boiling issues in a boat. Nor in my carb'ed cars and trucks even though they get much hotter. BUT it is interesting that you have and I don't want to discredit your input here.

It certainly can't hurt to change the intake gasket or put in a phenolic spacer to help keep the carb cooler. I still think slightly richening the idle screws will cure the issue.

dchatagnon
07-29-2005, 04:11 PM
Hello,

I had the same issue too when I switched to 4160 3 months ago. In fact, the factory adjustment of the carb was not good. One of the screw was just opened to half a turn and the opposite one @ 2 turns.... So, I just have turned-in both screws and then re-open them 1 turn. Now, the boat is running very good and the engine restarts right up.

Damien

martini
07-29-2005, 04:25 PM
There is a distinct possibility that climate may have had something to do with my issues. Only 500 to 700 feet above sea level and general summertime temperatures range anywhere from 95 to 100+, humid as hell too. I also am interested to see if adjusting the idle mixture will cure the problem and it may very well do just that.

jake
08-01-2005, 08:17 PM
Out is richer, in is leaner. To adjust, start on one side and turn screw in all the way, it may act like it is going to die so be prepared to quickly turn it back out again. Start turning the screw out again until you have achieved the highest idle, note how many revolutions you are turning it out. Proceed to the other side and repeat. It will generally fall somewhere between 1 full turn out and up to 2 full turns. Once you have achieved the highest possible idle with this adjustment, reduce or adjust your idle back to specs with the idle stop screw, not the mixture screws you just adjusted.

Do you do this with the engine warm or cold?

93ps205
08-01-2005, 11:21 PM
Well, I did back out each of the screws about 1/2 turn. Each screw was initially out
about 1 full turn from the seated position. So now they're each out ~1.5 turns.

I re-adjusted the idle to ~950rpms. Initial observation was that the problem was
completely solved. Tried several different scenarios of running the boat and
waiting different amounts of time. The boat started every time without the need
to pump the throttle. Seemed like the problem was solved.
However, later on in the day the problem creeped back again. The engine would
almost catch, but then would would not start in the neutral position. If I gave it one pump before starting, then it starts right up, or if I pull the pin and advance the throttle before cranking, again, it starts right up. This happened late in the day
Sunday. It was too late to start tinkering with the carb screws again. Maybe
they need to be out even further???

I guess I could live with this annoyance, but when I'm the one skiing and I someone
else is driving, it's a pain in the butt explaining from the water how the get the
bugger running.

east tx skier
08-01-2005, 11:44 PM
900 is a little high on the idle (rough on the transmission). Manual recommends 600 to 800 rpms at idle.

jake
08-02-2005, 02:14 AM
have you adjusted your choke? Black plastic housing on the driver side of your carb with two wires going to it.
1. Take the flame arrestor off so you can see the butterflies
2. Loosen the keeper screws
3. Turn the housing counter clockwise until the primary choke opens
4. Now turn it back just until the choke plate closes completely
5. Advance it one or two more "notches". (you'll see marks on top of the choke housing...it's useful to mark it where it is now so you know if it was adjusted correctly after re-adjustment)
6. Re tighten the keeper screws

I end up doing this three times a year, first in the spring when it's still cold out, then about mid June when the hot weather gets here, then again in the fall when it cools down again. Because the electric choke is a bi-metallic spring that heats up when current flows through it, the ambient outside temperature seems to affect it. Seems like alot of hassle, but it seriously only takes about a minute and a half couple times a year. Well worth it.

jake
08-02-2005, 02:18 AM
900 is a little high on the idle (rough on the transmission). Manual recommends 600 to 800 rpms at idle.

I've never had luck getting my boat w/ 4010 to idle bellow about 850 in neutral. Seems to run best when fast idle (cold w/ choke on) is about 900-920, and hot idle (warmed up choke open) is about 850. Goes down to about 700 in gear. If I adjust my idle down to 800, I have reliable start issues.

martini
08-02-2005, 10:32 AM
I agree with east texas, a little high on the idle. It should be in the 650 to 700 range in neutral.

93ps205, when you have this problem the next time. Feel the front of the carb(fuel bowl) and see if it hot to the touch. I still think you may have vapor lock/fuel boiling issue. How low can you make it idle?

Storm861triple
08-02-2005, 02:59 PM
have you adjusted your choke?
It's not the choke. The choke shoud have zero effect on the idle once warmed up for the day.

93ps205, I agree w/martini's test. Run it hard, let it sit for a minute (to heat soak), then pop the engine cover and grab the float bowl and see how hot it is. I'm guessing it'll be around 110-120*. but it's worth checking.

As for adjusting the idle screws, the STARTING point should be 1.5 turns out. Yours were too lean at 1 turn out when you started.

Also you absolutely want to make this adjustment while the engine is at operating temp.

To adjust the idle screws start at 1.5 turns out, and turn each screw in and out, a little bit and one at a time, trying to achieve the best (highest) idle you can. After you get there, reset your idle speed (throttle stop) and do it again as closing the throttle stop will make the idle mix screws more sensetive.

east tx skier
08-02-2005, 03:45 PM
I've never had luck getting my boat w/ 4010 to idle bellow about 850 in neutral. Seems to run best when fast idle (cold w/ choke on) is about 900-920, and hot idle (warmed up choke open) is about 850. Goes down to about 700 in gear. If I adjust my idle down to 800, I have reliable start issues.

I believe it. I never idled mine that high when I used the 4010 and had lots of issues (whether they were related or not, I don't know). But putting into gear at over 900 rpms seems to me that it would be a little hard on the transmission. I could certainly be wrong.

PegLeg
08-02-2005, 04:15 PM
Before I went back to my 4010 on my 93 PS205, I had to do a couple of things to my 4160 to get it to hot start, idle at 600 rpm and not stall when I put in gear. I set each idle screw at 2.25 turns out and opened up the secondary throttle plates a little(4160 list#80319 has an adjustment screw at the bottem of the carb just below the plates), not to the point that it uncovers the two transitions wholes, but just below them, this allowos you to still have adjustment with the idle screw and the boat doesn't poison your riders that are at the back of the boat with carbon monoxide. The sweet spot seems to be at about 1.75 turns out but it stalled when put in gear. And yes the fuel bowl on my 4010 is very hot to the touch after pulling a skier. I insulated the bottem of the both bowls(secondary has an idle circuit too) and fuel lines and use the 3/8 inch
Holley gasket and lower the float bowl slightly on my 4010. The 4010 is so much easier to work on and adjust(prettier too). Lex(good parts man) and Lex(Scooters Brother) at Rambo marine who I drink with agree that a holley is like any other mass produced item ever 2 out of 10 is a lemon. I guess you just have to make lemonade and not try to make orange juice(go Vols).

east tx skier
08-02-2005, 04:21 PM
Lex is the best parts man!

PeteS
08-02-2005, 07:48 PM
Well, I did back out each of the screws about 1/2 turn. Each screw was initially out
about 1 full turn from the seated position. So now they're each out ~1.5 turns.

I re-adjusted the idle to ~950rpms. Initial observation was that the problem was
completely solved. Tried several different scenarios of running the boat and
waiting different amounts of time. The boat started every time without the need
to pump the throttle. Seemed like the problem was solved.
However, later on in the day the problem creeped back again. The engine would
almost catch, but then would would not start in the neutral position. If I gave it one pump before starting, then it starts right up, or if I pull the pin and advance the throttle before cranking, again, it starts right up. This happened late in the day
Sunday. It was too late to start tinkering with the carb screws again. Maybe
they need to be out even further???

I guess I could live with this annoyance, but when I'm the one skiing and I someone
else is driving, it's a pain in the butt explaining from the water how the get the
bugger running.
I have an '88 with a 4160, and your hot start issues are identical to the ones I experience in my boat.

What I'm wondering is, what would happen if we set the air idle screws to run a little richer? Even though the idle may not be the highest or smoothest, would the richer air/fuel mixture allow for reliable hot starts? I won't be able to mess with my boat for a bit, as I'm on the road, but maybe the next time you use yours, give that a shot. Back out the air idle screws 2.75 or so turns and see if that changes anything for the hot starts.

You hit the nail on the head by stating it is more of an annoyance. Everytime there is a new driver, while your in the water trying to teach them how to start your boat up.

Peg Leg offered a few suggestions that may be worth trying as well, and I think one was a richer air idle mixture. What do you think?

PeteS
08-02-2005, 08:03 PM
Before I went back to my 4010 on my 93 PS205, I had to do a couple of things to my 4160 to get it to hot start, idle at 600 rpm and not stall when I put in gear. I set each idle screw at 2.25 turns out and opened up the secondary throttle plates a little(4160 list#80319 has an adjustment screw at the bottem of the carb just below the plates), not to the point that it uncovers the two transitions wholes, but just below them, this allowos you to still have adjustment with the idle screw and the boat doesn't poison your riders that are at the back of the boat with carbon monoxide. The sweet spot seems to be at about 1.75 turns out but it stalled when put in gear.
I'm curious as to how an adjustment to the secondary plates could help with hot start issues. I'm not down playing your claim at all though, as I'm willing to try anything to solve my problems.

93ps205
08-02-2005, 08:19 PM
Thanks for the suggestions. When I get back to the lake this weekend, I'll try again
to adjust the carb A/F screws for the highest idle. Further, I'll drop the neutral idle
down to ~700. Will see if this helps.

Question about the fuel boiling hypothesis: If indeed the carb bowls are hot
and it is possibly vapor lock, then what is the remedy?

Thanks again for all of the advice so far. Will keep the group posted on
the resolution.

Jim

PeteS
08-02-2005, 08:28 PM
Thanks for the suggestions. When I get back to the lake this weekend, I'll try again
to adjust the carb A/F screws for the highest idle. Further, I'll drop the neutral idle
down to ~700. Will see if this helps.

Question about the fuel boiling hypothesis: If indeed the carb bowls are hot
and it is possibly vapor lock, then what is the remedy?

Thanks again for all of the advice so far. Will keep the group posted on
the resolution.

Jim
I assumed that was my cause, so on mine I currently have my A/F idle screws adjusted to yield the highest idle, and my hot restart issues are still active.

That is why I was curious as to what the results would be from a setting creating a richer fuel/air mixture.

Good question on a solution for the vapor lock. Is there a remedy other than adding a spacer between the carb and the intake, or a new intake manifold gasket?

ryanar
08-03-2005, 01:41 AM
I have an 88 prostar with the exact same "hot start" issues. I just had the carb rebuilt (had a leak) and want to adjust the mixture screws to minimize the problem. Any advice? Specific's would help as Iím not Mr. Mechanic... X # of turns for the mixture screws and idle screw set for Y # of RPM's. Thanks in advance.

PegLeg
08-03-2005, 10:31 AM
The idle screw on the primary is the adjustment for the primary plates, but to get the carb to start and not stall when I put it in gear I had to adjust up to about 800-850 rpm which as everyone says is to high an rpm to engage the transmission, but I noticed that if I set the air screws about a half turn past the sweet spot(richer) this helped with the stalling(not enough air and fuel) so to equalize(this helps with hot start because it creats a semi lean condition which hot engines like) this mixture I opened the secondaries, not to the point of effecting tranision circuit, but enough to get more air into the carb, and this give a good exhaust smell and no sut on the boat and no stall when putting in gear. This is all trial and error stuff based on 20 years of racing dirt bikes(on a shoe string budget) and playing with boats behind my house on Clearwater Ski lake. All my buddies with new MCs think I'm a little annal about how my toys work/run/look, but thats just the engineer in me. *If you open the secondary plates to far you are getting back to a rich/flooding condition that hot engines dont like and are again hard to hot start because you uncover the transition holes.

PegLeg
08-03-2005, 10:42 AM
Make sure the vents on your motor box are not clogged by the foam insulation that the motor box is lined with, also Chris Craft has used/suggested high flow fuel pumps, water cooling and fuel line/carb insulation as cures for vapor lock. I insulated the carb and fuel lines on my 88 Chris Craft Cavalier and that solved the hot start problems. I did the same on my 93 MC PS205 with Holley 4010, just to be safe.

martini
08-03-2005, 10:52 AM
This is what worked on my boat and still does. As I stated before.

There is a heat spacer you can purchase that will insulate the carb from the intake manifold. It works perfectly, the carb never gets hot, just warm. It is a 1/2" spacer made from some type of composite material. You can get them at summitracing. They are cheap. You will of course need longer carb mounting studs, those are easily purchased through summit as well.

I believe I also gave another example of how to possibly fix this problem with new intake manifold gaskets sold by skidim. It's your choice, but the carb spacer DID solve my hot start/vapor lock issues.

PegLeg
08-03-2005, 11:40 AM
Phenolic Spacer on EBAY, $14.99

Storm861triple
08-03-2005, 01:14 PM
...What I'm wondering is, what would happen if we set the air idle screws to run a little richer?

That's what I've been suggesting this whole thread.

But 2.75 turns out is WAY too much. Start at 1.5 turns out, then w/the motor running and warm, "Feed it what it wants". When you find the optimal setting for the idle mix screws, you'll notice that there is a bit of a 'plateau' (maybe a 1/4 turn either way) where there is no dicernable difference in the idle speed or character. Since the motor wants more fuel for a good start, after the final setting, leave the screws on the richer side of that plateau, and it should start and run great.

FYI, although PegLeg had good luck w/it, I do not recommend trying to conrtol any aspect of idle w/the secondaries. This goes against everything I know and believe about setting up carbs. It apparently worked for PegLeg, but IMO, if you need "more air", open the primary plates some more, and adjust the idle mix screws accordingly. It doesn't matter where (which plates) the air comes though, except that making it all go through the primary side gives a stronger signal, and that gives you more control over fuel metering. Please stick w/the primary side first until all options on that side are exhausted before trying anything unconventional like holding the secondaries open.

-Tom

Double Overhead
08-06-2005, 05:12 AM
Just FYI im having this same issue on my S&S with the 4160. It seems to be more prevelent when im waiting to start it after about ten minutes of sitting without running. I basically put it on WOT and it starts right up.

Another issue that I am having is my boat starts right up at home on the first crank. Ater a 20 mile drive to the lake it doesnt want to start when I am on the launch ramp. Again I have to do the wide open throttle. It has a lot harder time during this compared to the hot start issue im having.

Storm861triple
08-06-2005, 05:03 PM
Just FYI im having this same issue on my S&S with the 4160. It seems to be more prevelent when im waiting to start it after about ten minutes of sitting without running. I basically put it on WOT and it starts right up.

Another issue that I am having is my boat starts right up at home on the first crank. Ater a 20 mile drive to the lake it doesnt want to start when I am on the launch ramp. Again I have to do the wide open throttle. It has a lot harder time during this compared to the hot start issue im having.

In both cases you need to determine something; whether you need more fuel or less to get it to start.

I SUSPECT, that when hot, you're a tad lean, and going to WOT gives you a healthy "pump shot" from the acclerator pump. It fires off that, then stays running on the main circuit. But since I don't KNOW, we need to run a little test... You can verify this one of several ways, but the easiest is to get it up to temp, let it sit for ten minutes, then rather than going to WOT, just give the throttle one full stroke (squirt of the pump), and then w/the throttle back in the neutral position, see if it fires right up. If it does, you COULD benefit from a slight richening of the idle mix screws (feed it what it wants). If it cranks and cranks but doesn't fire, then it's flooded and perhaps the idle screws are set too rich. Follow?

As for the cold start on the ramp vs. at home, the first thing that comes to mind is fuel slosh resulting from a high float level. Again, you need to verify if the thing is flooded by the time you get to the boat ramp, or if rather in going to WOT, you gave it a sufficient pump shot to get it to fire. Same test proceedure would apply here. Do the test above in both situations, and report back here.

-Tom

Double Overhead
08-07-2005, 06:37 PM
Storm - I am pretty sure the issue at the launch ramp is flooding. I opened the engine cover and I could smell some fuel and after letting it sit a little bit it started right up. When I am at my house the boat fires right up on the first crank with no throttle at all. Another time after launching, it took a minute to start and I saw a cloud of black smoke coming out of the exhaust just after it started. What would cause the floats to do this during hauling? Is it a matter of adjusting the float level or possibly a needle/seat problem?

During hot starts I also suspect it is flooding because on several occaions a I could see fuel dripping into the carb after we shut off the boat. Again, at WOT it starts like a champ. Any idea what would cause the fuel drip?

I am going out ot the lake in the morning and I will try the stuff you mentioned and let you know how it goes. I am going try to readjust the air/fuel while im out there.

I am planning on a carb rebuild after the summer. It is more of an annoyance at this time. I am trying to troublshoot it before I rebuild the carb.

Storm861triple
08-08-2005, 07:54 PM
When I am at my house the boat fires right up on the first crank with no throttle at all. Another time after launching, it took a minute to start and I saw a cloud of black smoke coming out of the exhaust just after it started.
Sounds like it's rich. I think you're right.

The higher the float level is set, the easier it is for gas to get from the float bowl to the discharge nozzle. If the float bowl is way too full, like when the float/needle/seat aren't working properly, and the bowl floods, fuel will run out of the discharge nozzle (and out the float vent too, but that's not what I'm getting at here). If your float level is too high, it's possible that driving it to the lake, the fuel will slosh around in the bowls and could run out the dischrage nozzles, flooding the engine. When you're still at your house, everything has been stationary, and I suspect that it starts w/o a pump form the throttle due to the high float level alone. That's my theory at this point w/the info I have now.

-Tom

PeteS
08-09-2005, 11:44 AM
That's what I've been suggesting this whole thread.

But 2.75 turns out is WAY too much. Start at 1.5 turns out, then w/the motor running and warm, "Feed it what it wants". When you find the optimal setting for the idle mix screws, you'll notice that there is a bit of a 'plateau' (maybe a 1/4 turn either way) where there is no dicernable difference in the idle speed or character. Since the motor wants more fuel for a good start, after the final setting, leave the screws on the richer side of that plateau, and it should start and run great.

FYI, although PegLeg had good luck w/it, I do not recommend trying to conrtol any aspect of idle w/the secondaries. This goes against everything I know and believe about setting up carbs. It apparently worked for PegLeg, but IMO, if you need "more air", open the primary plates some more, and adjust the idle mix screws accordingly. It doesn't matter where (which plates) the air comes though, except that making it all go through the primary side gives a stronger signal, and that gives you more control over fuel metering. Please stick w/the primary side first until all options on that side are exhausted before trying anything unconventional like holding the secondaries open.

-Tom
Thanks for your thoughts, Tom. They sound right on cue to me. I'll go on the richer side (screws out) for the air idle adjustment and see if that helps on my hot re-starts.

Although, someone on here mentioned that for hot re-starts specifically, the motor may want the mixture leaner? What would be your thoughts on that?

Storm861triple
08-10-2005, 10:53 AM
Although, someone on here mentioned that for hot re-starts specifically, the motor may want the mixture leaner? What would be your thoughts on that?
Generally, when motor is warm, the fuel vaporizes better in the intake, and stays "in suspension" w/the air better then when it's cold. Due to this, when it's cold, you need more fuel (richer) so that by the time the air makes it to the cylinder the amount of fuel that's in suspension and vaporized is sufficient to keep the motor running; the rest of the fuel is all over the walls and floor of the cold intake, on a cold motor. That is what the choke is for: to deliver the proper fuel to the cylinders when the motor/intake, etc. is cold.

Although that is GENERALLY how it works, the simple fact is that in your case, the motor needs more fuel to start quick and easily, and this has been proven by your "pump-shot-then-start" proceedure which works (same as on my boat at low elevation). That proves that your motor want's more fuel. So, my thoughts on all this is same as what I said above: "Feed it what it wants". Don't be driven by hearsay and general theory-talk -that's good for getting it "in the ball park", but every motor is a little different and you need to give them what they like. Just give your motor what your motor wants, and your results will be satisfying. :)

PeteS
08-15-2005, 10:19 AM
As an update for those who are experiencing similiar problems to mine, Tom was right on target with his suggestions. I simply re-tuned my air/idle circuits for maximum idle, then increasingly opened one side (richer air/fuel mixture) until I noticed a slight drop in the idle RPM. At that point, I brought it in ever so slightly -- and did the same to the other side. That was it. My idle is still strong, with maximum RPM's and the hot start issues are no more. It fires quickly, even after 20 minutes of sitting without throttle priming, etc. Thanks for your help, Tom.

For anyone who is having trouble with this issue, try this method before taking active measures to solve a vapor lock, or fuel boil problem.

Storm861triple
08-15-2005, 03:37 PM
Glad I could help, and I'm glad it worked out for you.

Feed it what it wants. :)

-Tom

Jimmy O
08-15-2005, 06:16 PM
Speaking of carbs. Does anyone have a spare 4010 they would like to sell for rebuilding/ spare parts? Thanks, J.O.

93ps205
08-15-2005, 11:14 PM
Generally, when motor is warm, the fuel vaporizes better in the intake, and stays "in suspension" w/the air better then when it's cold. Due to this, when it's cold, you need more fuel (richer) so that by the time the air makes it to the cylinder the amount of fuel that's in suspension and vaporized is sufficient to keep the motor running; the rest of the fuel is all over the walls and floor of the cold intake, on a cold motor. That is what the choke is for: to deliver the proper fuel to the cylinders when the motor/intake, etc. is cold.

Although that is GENERALLY how it works, the simple fact is that in your case, the motor needs more fuel to start quick and easily, and this has been proven by your "pump-shot-then-start" proceedure which works (same as on my boat at low elevation). That proves that your motor want's more fuel. So, my thoughts on all this is same as what I said above: "Feed it what it wants". Don't be driven by hearsay and general theory-talk -that's good for getting it "in the ball park", but every motor is a little different and you need to give them what they like. Just give your motor what your motor wants, and your results will be satisfying. :)
Tom,

Thanks for all of your help. This past weekend, I too seem to have
success using your suggestions. I backed out both mixture screws
until the highest idle was achieved. Then I lowered my idle speed
down to ~750-800. I noticed that if I tried to drop the idle any lower
than 750, the engine began to have a noticable surge. Tried the boat
for several runs on Sunday and never had to assist starting
by pumping the throttle. Again, thanks for all of the help and good
discussion.

Jim
93ps205

Wes
08-16-2005, 12:05 AM
Jimmy O

I have a spare 4010 sitting in the garage. I replaced mine with an Edelbrock. Give me an PM if you are interested.

Wes

Jimmy O
08-16-2005, 09:53 AM
Hi Wes. What would you want for the carb. Thanks, J.O.

Storm861triple
08-16-2005, 12:02 PM
I noticed that if I tried to drop the idle any lower
than 750, the engine began to have a noticable surge.
'93ps, That's great you had success too. I did want to point out one thing and this may not be worth pursuing if you're satisfied w/the way it's running at the moment. But if you want to go a little farther, the surging is often a sign of a lean A/F ratio.

When you adjust the mixture screws and the idle speed increased, then you brought it back down by closing the throttle plates....doing that makes the idle circuit more sensetive, and you can often go through both sides one more time and get a little more adjustment out of both screws, as a result of the increased sensetivity. After the second round you can make a final throttle stop (idle speed) adjustment.

Doing that is kind of like "Marginal Utility"; every time you close the throttle some and adjust again, you realize a smaller benefit from the same effort. But it's usually beneficial to go through the process at least twice.

Like I said above though, if you're happy w/the way it is at the moment, then you might just want to leave it. :) Glad to hear it's better so far though.

-Tom

Wes
08-16-2005, 01:45 PM
Hi J. O.

I am sure $60 and you pay shipping would work.

Wes

Jimmy O
08-17-2005, 10:21 AM
Hi Wes. That would work. I'll give you my email address: jim.ostrander@city.saskatoon.sk

We can then exchange addresses etc. Thanks, J.O.

Jimmy O
08-17-2005, 10:24 AM
Wes. Thats jim.ostrander@city.saskatoon.sk.ca. I think i forgot the ca

Wes
08-17-2005, 02:01 PM
Sounds good Jim,

I will drop you a line after work tonight.

Wes

Star92
08-23-2005, 11:16 PM
This is a great thread for carb adjusting. I dealt with these same issues when I first got my boat. When cold, first off the trailer, it was hell trying to keep it running. Had issues with engine dying after runs and would not idle, ect...I first adjusted my choke, correcting the off the trailer problem. The previous adjustment basically had the choke inoperable. I also had a problem with high idle issues, the engine would only idle at about 950 r.p.m.'s. It didn't take long to realize that this could not be good on the tranny. I did exactly what is stated in this thread, and have got my boat where it will idle smoothly at 750 r.p.m.'s, drops into gear as smooth as a baby's but. I then still had issues with the engine dying after a long run, and refusing to idle. I previously posted about this problem early this summer. I finally broke down and did the dreaded carb rebuild. I kick myself in the but everytime I crank her up for not doing it three years ago. The rebuild was very simple, and inexpensive(got kit from skidim). My 92 190 runs smoother and better than my previous 94 205 E.F.I. I wouldn't trade it for a new one. With the help from this site I now have a boat that runs probably better than when it was new. Thanks to everyone here.

east tx skier
08-24-2005, 12:32 AM
It's a great feeling I know. Nothing worse then sitting in the water and watching someone struggle to keep your boat idling before they pull you up.

OSUspenc99
08-24-2005, 09:58 AM
hey guys it seems like i am having some of the issues listed here. Here is what is going on. I am out on the water all day and everything is running fine. At the end of the day when i am trying to pull the last skier my boat starts to sputter on Acceleration. Then when you kill the engine to pick up the skier out of the water that you can not get skiing it is hard to restart. Once you get it started it will die when you put into gear again. I was going to go purchase a rebuild kit today and just do that. Do you think it is something that i just need to adjust or should i just do the rebuild?

Storm861triple
08-24-2005, 10:42 AM
Just do the rebuild.

It sounds to me like youre accelerator pump MAY be suspect, and you probably need to adjust the idle screws too, but to get a accel pump, you need to buy the wholel kit anyway, and it's only a few bucks either way. Just do it.

You can verify the pump operation when it's hesitating by removing your flame arrestor, and actuating the throttle by hand. It should shoot fuel on the primary side discharge nozzels instantly.

As for adjusting the idles screws, it's been covered in this thread already. Start 1-1/2 turns out, and feed the engine what it wants from there.

OSUspenc99
08-24-2005, 10:48 AM
ok here is my other question.
Is their a difference between a marine holley carb and a truck holley carb. I was looking for a rebuild kit at napa and i also called mastercraft. Napa said that it was 75 bucks for the marine rebuild kit. I called mastercraft and they said that they are the same and theirs was only 49 bucks. anyone know about this?

PeteS
08-24-2005, 11:00 AM
The trick becomes keeping the in-gear idle at 600 rpm (as specified by the manual), all the while not stalling, maintaining strength, and pump-free hot restarts.

Just for reference, I've obtained that by setting my idle around 670 out-of-gear, and my air-idle screws backed out 2.25 full turns.

PegLeg
08-24-2005, 11:09 AM
Rebuild with Holley/DG master rebuild kit

Which carb, 4160 or 4010. If you get the master rebuild kit, then you can get a can of Berrymans Chem Dip and let all the hard parts soak over night, this not only makes the carb look new, but also cleans out all the small passages, and basically you have a new carb.

Storm861triple
08-24-2005, 05:08 PM
Is their a difference between a marine holley carb and a truck holley carb.

Depends on the model holley that's on the truck. If it's a 4160, then yes, the kits woudl be interchangeable. Buy the cheaper kit.

-Tom

jake
08-26-2005, 09:57 AM
OK, new issue. Carb was doing pretty good, now when I adjust the idle, say down to 700 rpm it will be running great until I take a ski run, then after the set the idle will be up at like 1200 rpm. If I adjust it back down at this point, next time I turn it off and restart, the idle will be too low to keep the motor running without advancing the throttle. Then if I speed it up again to ~700, I get the same high idle problem after the next ski set. Vicious cycle! Any suggestions?

Facts: 93' 4010 has never been rebuilt. Planning to do so this fall, but want to get this problem solved for now. Air fuel mixture screws are set to 2 1/2 turns out on each side.

Storm861triple
08-26-2005, 02:48 PM
Check your throttle return spring and then the primary side throttle shaft bushing. To check the bushing, you need to remove the throttle cable from the carb linkage. Open the throttle on the carb w/your hand some, then try to shake the linkage to see if there is any slop or movement of the throttle shaft in the casting. If there is, that could be your problem -causing the throttle plates to "hang open" if the aren't centered correctly in their bores when you slow down after a ski.

The other thing you could do is come down after a ski, when it's "high idling", open the engine cover and fiddle w/the throttle linkage (not the idle screws), just the mechanism itself, and see if playing w/it, "bumps" it down. If it does, then you need to figure out what is holding it open.

It could be the secondary plates that are snagging on something too.

Check that stuff first, then report back.

-Tom

herevard
08-27-2005, 05:27 AM
ADJUSTING THE IDLE
1) Adjustments, to be precise and accurate, must be made when the vehicle is on level
ground.
2) 2) Seat the idle adjusting needles lightly and back each off a full turn if there is any doubt about this not having been done during reassembly.
NOTE
Care must be taken when seating the idle adjusting needle not to turn the screw tight against the seat, grooving the tip of the needle. If the needle becomes grooved, a smooth idle cannot be btained.
3) Start the engine and allow the opera ting temperature to reach normal.
4) After the engine reaches its normal operating temperature, adjust the idle speed screw to idle the engine at the specified rpm.
5) First set one of the two idle adjusting needles for the highest steady manifold vacuum reading. If a vacuum gage is not available, obtain the smoothest running, maximum idle speed by turning the idle adjusting needle in until the rpm begines to drop off, then backing the needle off over the "high spot" until the rpm again drops off. Set the idle adjusting needle halfway between these two points for a satisfactory idle mixture setting. Then repeat the procedure with the other needle. Should these adjustments show an increase in idle rpm, reset the idle speed screw to obtain the specified idle rpm and adjust the idle adjusting needles again.

Storm861triple
08-29-2005, 12:26 PM
ADJUSTING THE IDLE
1) Adjustments, to be precise and accurate, must be made when the vehicle is on level
ground.
2) 2) Seat the idle adjusting needles lightly and back each off a full turn if there is any doubt about this not having been done during reassembly.
NOTE
Care must be taken when seating the idle adjusting needle not to turn the screw tight against the seat, grooving the tip of the needle. If the needle becomes grooved, a smooth idle cannot be btained.
3) Start the engine and allow the opera ting temperature to reach normal.
4) After the engine reaches its normal operating temperature, adjust the idle speed screw to idle the engine at the specified rpm.
5) First set one of the two idle adjusting needles for the highest steady manifold vacuum reading. If a vacuum gage is not available, obtain the smoothest running, maximum idle speed by turning the idle adjusting needle in until the rpm begines to drop off, then backing the needle off over the "high spot" until the rpm again drops off. Set the idle adjusting needle halfway between these two points for a satisfactory idle mixture setting. Then repeat the procedure with the other needle. Should these adjustments show an increase in idle rpm, reset the idle speed screw to obtain the specified idle rpm and adjust the idle adjusting needles again.
Hmmm. I think I've heard that somewhere before..... :D
Start at 1.5 turns out, then w/the motor running and warm, "Feed it what it wants". When you find the optimal setting for the idle mix screws, you'll notice that there is a bit of a 'plateau' (maybe a 1/4 turn either way) where there is no dicernable difference in the idle speed or character. Since the motor wants more fuel for a good start, after the final setting, leave the screws on the richer side of that plateau, and it should start and run great.

Notice that since we're talking about a lean-hard start issue here, I recommend leaving the final setting on the rich side of the platue, rather than in the middle like that cut-and-paste instruction reads.

-Tom