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View Full Version : Prostar 351, stalls in reverse or when going in to gear.


College Kid
08-07-2012, 11:40 AM
I have read so many threads on tune carbs and adjusting idle, so thanks in advance, but I just can't seem to dial in enough to make this issue go away. Looking for other things to start to try, or maybe I am missing something.

The PO installed a Holley 4160 last winter but was never able to tune it. He installed it do to the fact that he could never get the boat to idle properly. I was able to get it "tuned in" while on land to around 700-900 rpm. But still have issues when on the lake, seems to need quite a bit of gas when first starting out. Once the engine was warmed up it was is fine going into reverse and forward. I shouldn't say warmed up but when you’re running at speed then slow down and need to reverse (i.e. when you’re picking up a skier) it runs fine.

But as soon as you idle or shut off the engine it seems to have the same issue. Or even at low speed it seems to be pretty quick.

I am no mechanic, but I do my own work on my trucks and have a lot of experience boating with outboards and I/0.

What am I missing? What should I check next? What is the best way to set the idle arm? I am thinking that might be my problem but I am not sure how best to adjust it.

SilviaMan
08-07-2012, 12:28 PM
We found that our 76 would idle to fast when warm if we adjusted it to idle well cold. So we deal with the warm up time to get her to idle. Normally its only 1 - 2 minutes before she'll idle on her own.

thatsmrmastercraft
08-07-2012, 12:42 PM
Ant time there is a running/stalling issue, the ignition system basics need to be addressed first. Spark plugs, distributor cap & rotor, points (if not converted to electronic ignition), timing and spark plug wires. Next would be carb basics. Is your electric choke operating properly? This could be your problem. It should be almost completely closed on a cold start, and open fully within a minute or so. Next is to check for a carb base gasket leak. This will make for a lousy running boat when it's first started up.

College Kid
08-07-2012, 05:36 PM
Ant time there is a running/stalling issue, the ignition system basics need to be addressed first. Spark plugs, distributor cap & rotor, points (if not converted to electronic ignition), timing and spark plug wires. Next would be carb basics. Is your electric choke operating properly? This could be your problem. It should be almost completely closed on a cold start, and open fully within a minute or so. Next is to check for a carb base gasket leak. This will make for a lousy running boat when it's first started up.

Thanks so much for this check list. Now for the start of my learning process, first off,

How do I tell if the PO did the electronic ignition? What does it look like? Pictures would be very helpful.

College Kid
08-07-2012, 06:06 PM
double post

thatsmrmastercraft
08-07-2012, 07:02 PM
Points mechanically open and close (left picture). Middle pic shows E.I. installed in a distributor, and a points distributor on the right.

Dino Don
08-08-2012, 01:57 PM
Also bear in mind there is an adj for the back throtle plate that has to be right. Small screw underneath the base plate that can only be reached with the carb off. Throtle plate has to have just enough gap .o10-.020 so you can balance it off with the frt adj screw. Too close it's messed up and too wide and you can't slow it down from the frt. adj.

College Kid
08-08-2012, 08:04 PM
Thanks everyone for the help. Bear with me now as I work through this. I am pretty new to working on a carburated engine/engines in general.

I am going to be checking timing shortly as I am trying to track down a timing light. Does anyone know of a walk through "how to" for that? I have searched but not come up with anything specific to my engine, ie where the hash marks are etc.

Also I took off the cap and took a quick picture can someone confirm that there is no electronic ignition on it?
Thanks!

thatsmrmastercraft
08-09-2012, 01:51 AM
Yup, those are points in there.

College Kid
08-09-2012, 11:56 AM
Thanks, guess I'll add electronic ignition to my winer project list.

LYNRDSKYNRD
08-09-2012, 11:57 AM
Timing light can probably be borrowed from local Orielly,Autozone, or other parts store.

College Kid
08-09-2012, 01:29 PM
Ant time there is a running/stalling issue, the ignition system basics need to be addressed first. Spark plugs, distributor cap & rotor, points (if not converted to electronic ignition), timing and spark plug wires. Next would be carb basics. Is your electric choke operating properly? This could be your problem. It should be almost completely closed on a cold start, and open fully within a minute or so. Next is to check for a carb base gasket leak. This will make for a lousy running boat when it's first started up.

The short answer is NO!!! lol it's not even hooked up!!!!!!!! I asked you all to bare with me so thanks!!!! I just had a look at the boat again to move on to the next areas to look over ie choke and if it is set properly. And I find it not connected at all... (you know that voice in your head that tells you what you are, mine went nuts on me). The previous owner did install the new 4160 over the winter and I remember him mentioning to me that it would need a bit more work, but the boat had run OK so far that I figured it was just tuning.

I found instructions for the Holley electric Choke install and am following the directions, and now have a few questions. There are a number of small electric wires in the engine that I have traced that don't end up anywhere so I am figuring that some of them must be choke.

Can someone please advise me on which would be negative and which positive?

I am assuming this one that goes to the stern of the engine is the positive.


And the one that is going to one of the posts on (sorry don't know what to call it) resistor from the distributor????? would go to the negative?

thatsmrmastercraft
08-09-2012, 02:53 PM
Now we are getting somewhere. Generally ground wires in boats are black, and colored wires are positive. What you need to determine this is a simple 12 volt test light, or a voltmeter.

You want a keyed ignition power wire for the choke positive connection. Keyed ignition means the wire has power when the key is in the crank and on positions, but no power when the key is in the off position. You can check this with the voltmeter of test light connected to ground, and to the wire in question. The purple wire to the coil should be keyed ignition. The PCM wiring diagram shows there should be a red wire for that.

For testing a ground wire, connect the test light or voltmeter to battery positive, and check for a black wire that will complete the circuit and light the test light or show battery voltage. there should be a black wire in the vicinity.

Keep in mind you never know what kind of fiend owned your boat previously and what kind of odd things they did.

College Kid
08-09-2012, 04:29 PM
OK,

So I did a little playing and have the choke moving. I am going to be running the purple wire from the coil (thanks for wording) to the positive side. and I am going to create a small grounding wire. Where would be a good place close to the choke to ground to? Any suggestions?

Also it looks as thou the purple wire on the stern of the engine runs back out of the wiring harness which I am assuming runs up to the switches. Could this be for the missing blower?

thatsmrmastercraft
08-09-2012, 05:20 PM
You may need to adjust that choke. On a cold engine, the choke blade should just close. After a minute or so of running (or key on) the choke blade should be completely open.

I connected to an existing ground wire at the starboard rear of the engine. I would think there must be a ground wire that you can splice into.

Not sure where the blower is on your boat. I guess I don't even know what year boat.

You can determine if you have the blower wire by turning on the blower (as if it were there) and looking for power.

College Kid
08-09-2012, 05:27 PM
I guess that info might be useful for future reference. It's a 92 PS 190.

College Kid
08-09-2012, 06:15 PM
Thanks again for all your help. Just wired it and it seems to be opporating correctly. Although I had to use the wire from the stern wiring loom/breaker area, as it didn't seem to work with the wire from the coil.

I am now curious what the purpose of that wire might be. any ideas?

I am going to try starting the boat up with a fake a lake and see how it goes, although the issue seemed to be much more present on the water.

Thanks again everyone!!! Don't know where I'd be without forums like these.

thatsmrmastercraft
08-09-2012, 06:20 PM
Nothing magical about which keyed ignition and ground get attached. Very little current draw, and only for a minute. Glad to hear things are progressing. Keep us posted.

College Kid
08-09-2012, 08:16 PM
So back to the issue, The choke is working as it should I think. Open not at all cold, takes about 1 to 1.5 to open up.

Issue now is that I can't seem to dial in the idle. I can get it as low as 1200 rpm and it sounds pretty good, anything lower anId its not very happy. I think I read that it should be around 700 or so on land? Is that correct?

I was able to get it to go down to 800 but it would fluctuate between that and 1000.

So what is next?

tockit
08-09-2012, 09:02 PM
Is your electric choke operating properly? This could be your problem. It should be almost completely closed on a cold start, and open fully within a minute or so.


The short answer is NO!!! lol it's not even hooked up!!!!!!!! I asked you all to bare with me so thanks!!!! I was able to get it "tuned in" while on land to around 700-900 rpm. But still have issues when on the lake, seems to need quite a bit of gas when first starting out. Once the engine was warmed up it was is fine going into reverse and forward. I shouldn't say warmed up but when you’re running at speed then slow down and need to reverse (i.e. when you’re picking up a skier) it runs fine.

But as soon as you idle or shut off the engine it seems to have the same issue. Or even at low speed it seems to be pretty quick.Not to rain on your parade, but if it's still stalling out when it's warm, it probably ain't the choke.

The choke being inop might will help your cold start a little, but most likely you've got something else going on.

It could be a vacuum leak though, like mrmastercraft mentioned. Spray some carburetor cleaner around the carburetor when the engine is idling and see if it speeds up.

Could also be your idle air mixture is off, timing is off, or about half a dozen other issues.

I would start by verifying you don't have any vacuum leaks if it were me.

tockit
08-09-2012, 09:08 PM
So back to the issue, The choke is working as it should I think. Open not at all cold, takes about 1 to 1.5 to open up.

Issue now is that I can't seem to dial in the idle. I can get it as low as 1200 rpm and it sounds pretty good, anything lower anId its not very happy. I think I read that it should be around 700 or so on land? Is that correct?

I was able to get it to go down to 800 but it would fluctuate between that and 1000.

So what is next?Take the two screws on the side of the primary bowl, with the engine running, and screw them all the way in.

Your engine should die.

Now screw them both equally out 1-1/2 turns. Start your engine and screw both screws in slowly (equal amounts) until your engine speed smooths out and seems to run the best.

You may have to go out with the screws (richer), but you usually have to go in (leaner).

It shouldn't take much, maybe 1/8 to 3/4 of a turn if everything else is working right.

And make sure both left and right screws are adjusted the same.

thatsmrmastercraft
08-10-2012, 12:24 AM
tockit has you on the correct path.

1. Vacuum leaks around carb base. If air is leaking underneath the carb, you are going to be lean no matter what you do.
2. Point gap check minimum (prefer to go with dwell as it is substantially more accurate) Replace if necessary....bad points surface will look pitted.
3. Condition of distributor cap & rotor. If any crud on contacts...scrape it off. Replace if necessary.
4. Verify timing.
5. Verify correct spark plugs, condition and correct gap. Replace if necessary.
6. The balance between mixture screws and idle speed screw is easily thrown out of whack. If the idle mixture screws are turned in too far, not enough fuel can be provided for adequate idle speed and the idle speed screw needs to be turned out far enough to open the throttle blades to the point where fuel is provided by the main operating circuit. If the idle screws are out too far, it is hard to get decent idle quality as it will be rich no mater what you do. Screwing them in all the way, then backing out 1 1/2 turns is where to start. Small adjustments from this point.

Any one, or more of these will cause poor idle quality. You need to verify all, even if you find one that seems to clear it up.

College Kid
08-10-2012, 12:48 AM
Thanks guys, looks like it's going to be fun weekend......


Honestly thou, I am feeling pretty positive about getting the choke fixed up, and it will be great feel confident in the engine at the end of this.

thatsmrmastercraft
08-10-2012, 12:56 AM
Getting the choke open may well be the main issue, but you need to ensure all the basics are in order. Working through the list will go quicker than you think.

College Kid
08-10-2012, 05:35 PM
Well I took the afternoon off work; I was too excited to get down to figuring this all out.

Started by picking up a feeler gauge to check point’s gap. As well as a bottle of carb cleaner to look for leaks.

I am wondering if anyone has a good write up on how to set the gap on the points? I don't have access to a dwell monitor right now, although I wouldn't know what to do with that either, so a write up for that would be good too.

I cleaned off the contacts in the cap with emery paper and have attempted to set the gap, although I am not sure if I am doing it correctly. It wouldn't turn over when I set the two points on the end but I was able to get it going setting the centre contact and the contact on the post set at .018? Am I on the right track?

I sprayed the carb cleaner around the base of the carb to look for vacuum leaks and thought I noticed a slight increase in rpm's. I started by checking if the all the bolts holding the carb down were tight and found that I was able to tighten them about 2 turns or so a piece very easily.

As I am sure you can tell I haven’t work on distributors before and I am not entirely sure what to look for to tell if they are worn out.

All of the wires and spark plugs look good, although I may replace the plugs as a precaution just in case.

I did set the screws on the carb as instructed and needed to turn them out 2 more turns to keep the engine going. I was able to play with the idle to make it run around 1000 rpm with these settings. Funny thing is it won't stay put and surges up to 1100 rpm........ I am thinking this might be a key for one of you genius to help diagnose

Thoughts?

thatsmrmastercraft
08-10-2012, 06:17 PM
The fact that the carb was a loose as it indicates the base gaskets are probably in need or replacement. Be sure to replace both gaskets (between the intake & spacer, and between the spacer & carb).

HERE (http://www.allpar.com/fix/points.html) is a pretty good write-up on setting your points.

I would invest in a new set of points. Old points can give you plenty of issues.

I suspect that your carb is dirty. Remove the mixture screws and insert the plastic tube from the carb cleaner and spray out the passages. If they are clogged up, it may spray back at you. Good time to be wearing safety glasses. Then replace the screws and see if you can get closer to that 1 1/2 turns out to get a decent idle.

thatsmrmastercraft
08-10-2012, 06:20 PM
HERE (http://www.amazon.com/Actron-CP7605-Tachometer-Voltmeter-Analyzer/dp/B00062YUUS/ref=sr_1_1?ie=UTF8&qid=1344633506&sr=8-1&keywords=dwell+meter) is an example of a inexpensive dwell/tach meter.

College Kid
08-10-2012, 06:29 PM
The 4160 carb was just installed in the spring and only run about 15 times this season, would it really be dirty already?

I am thinking of dropping down to the parts store and finding a new points. I realized that I am not sure what sort of distributor I have, I know there is the Mallory or Prestolite, Is there a difference in the points in these units? Also was trying to track to down electronic ignition locally as I figure it might be easier to just upgrade now. Was asked if it was dual or single point style distributor. After researching I am thinking it is a dual, correct?

thatsmrmastercraft
08-10-2012, 06:37 PM
Is the carb new or rebuilt? it shouldn't be giving you any running problems if it is that new. You should be much closer to the 1 1/2 turns out on the idle mixture screws.

There will be a tag on the side of your distributor which will identify it. Not sure on the difference on points between the two. I used to buy points from the local auto supply store that were for a 1975 f150 with a 351W. Should be a single point dist.

You might not find anyone that stocks an electronic ignition for your boat. I ordered my Pertronix ignition and coil through Amazon. I went to the Pertronix site where I entered my distributor number to ensure I was getting the correct electronic ignition kit.

tockit
08-10-2012, 07:16 PM
Is the carb new or rebuilt? it shouldn't be giving you any running problems if it is that new. You should be much closer to the 1 1/2 turns out on the idle mixture screws.Mrmastercraft's right. Something doesn't sound right if you had to set your idle mixture screws 3-1/2 turns out. That's pretty rich.

Your carburetor must be sucking in air from somewhere else (vacuum leak leaning out your mixture) possibly?

It's all pointing to your carburetor, especially with you being able to tighten your base bolts two turns.

Check all the screws around your vacuum secondary as well (driver's side of carb) and make sure they're tight. Mine have backed out before and it made it idle rough.

College Kid
08-10-2012, 08:28 PM
Thanks for all the help guys,

tockit with your wording about the carb "sucking in air" you have me thinking.......I have always noticed what a sucking in noise that the carb makes is this normal? You can really hear it pulling the air through the flame arrestor. Could it be possible that it is that obvious?

I couldn't find any leaks between the block and the carb adaptor, but I am wondering if there is another area I should try the carb cleaner trick?

tockit
08-10-2012, 08:43 PM
Thanks for all the help guys,

tockit with your wording about the carb "sucking in air" you have me thinking.......I have always noticed what a sucking in noise that the carb makes is this normal? You can really hear it pulling the air through the flame arrestor. Could it be possible that it is that obvious?

I couldn't find any leaks between the block and the carb adaptor, but I am wondering if there is another area I should try the carb cleaner trick?Your probably not gonna hear a vacuum leak unless its a big one.

Check all the screws around your vacuum secondary (driver's side of carb).

Make sure those are all tight. Mine have backed out before and it made it idle rough. If those screws get loose, your secondary can leak in between where it mounts on the side of the carburetor.

Also check the vacuum lines going to your carb. They shouldn't have any leaks either.

thatsmrmastercraft
08-10-2012, 09:04 PM
There is some sucking noise from the air going through the flame arrester. How clean is this? Could be restricting air flow. If needed, use more carb cleaner to clean the thing out.

Any luck finding points?

cbryan70
08-10-2012, 09:17 PM
if the timing was way off couldn't it cause all of this?

College Kid
08-10-2012, 09:22 PM
Cleaned the flame arrestor today with break clean. So check there.

Picking up points in the morning, or if I can find it go with electronic ignition.

Going to pull off the carb and re check everything is buttoned down.

Still need to check timing, and am going to do that tomorrow as well.

Hopefully by noon tomorrow I will have some news. or I'll have disapeared to the lake!!!!!

tockit
08-10-2012, 09:50 PM
Going to pull off the carb and re check everything is buttoned down.

Still need to check timing, and am going to do that tomorrow as well.

Hopefully by noon tomorrow I will have some news. or I'll have disapeared to the lake!!!!!Why are you pulling the carb off?

You can check for vacuum leaks without pulling it off.

You could actually induce a leak by removing and reinstalling it.

College Kid
08-10-2012, 10:37 PM
hmmmm,

I was thinking I would re do the gasket between the carb and block to confirm that there was no leaks there. or do you think this should be a last resort? Better to clean up all other possibilities first?

thatsmrmastercraft
08-11-2012, 10:53 AM
If the carb hasn't been on there all that long, and you don't get an increase in RPM by spraying carb cleaner around the base of the carb, replacing the gaskets will just be a waste of time and money.

mtajpa
08-11-2012, 11:13 AM
Does your engine have a PCV valve? It may be gould causing a vacuum leak. It would be located on one of the valve covers with a hose going to the intake manifold. You can test it by just pulling it out of the valve cover with the engine running and put your thumb over it. If you have no change in idle then its probably not leaking. You can also clean this with carb cleaner.

College Kid
08-11-2012, 02:26 PM
I do have a PCV valve, I'll check it as well. Best to pull it at the valve cover or better to pull it from where it enters the carb?

mtajpa
08-11-2012, 03:02 PM
Pull it out of the valve cover and plug with you thumb.

j.mccreight@hotmail.com
08-11-2012, 05:07 PM
What does it mean when you shake the pcv valve and it rattles?

College Kid
08-11-2012, 08:02 PM
OK a little bit of an update, after a couple trips to the shops I have switch over to the Pertronix Ignitor EI. I had the hardest time trying to find a new set of points and decided to bit the bullit and just switch over. It started up great on the first time, but as soon as the choke become fully open it stalled out. I have re set the carb screws back in to a 1 1/2 turns in but can't seem to get it to idle below 1000 rpm. and it is still surging about 100 rpm forward.

I did check the PCV valve and it seems to be loose and fine. Although I did notice that there were no hose clamp holding it on and wonder if I could be getting some sort of leak there?

I still need to check timing and unfortunatly the parts stores around here don't loan them out. I have a friend coming by tomorrow with one so we can check it.

Is there anything else that I should be checking over since switching to EI?

Cloaked
08-11-2012, 08:28 PM
OK a little bit of an update, after a couple trips to the shops I have switch over to the Pertronix Ignitor EI. I had the hardest time trying to find a new set of points and decided to bit the bullit and just switch over. It started up great on the first time, but as soon as the choke become fully open it stalled out. I have re set the carb screws back in to a 1 1/2 turns in but can't seem to get it to idle below 1000 rpm. and it is still surging about 100 rpm forward.

I did check the PCV valve and it seems to be loose and fine. Although I did notice that there were no hose clamp holding it on and wonder if I could be getting some sort of leak there?

I still need to check timing and unfortunatly the parts stores around here don't loan them out. I have a friend coming by tomorrow with one so we can check it.

Is there anything else that I should be checking over since switching to EI?Timeing is about the only thing that you need, as you stated. Are you adjusting the choke as you tweak on the tuning? The choke can be adjusted by loosening the three screws and turning the body of the electric choke to meet the needs of the setting. There is also a possibility that the choke mechanism (the internal coil) can be faulty. Doesn't take much to change the choke setting. I'd adjust accordingly, i.e. when the engine is warm to idle or throttle up (if you're running it in the driveway) the choke should be open. If it's not, then loosen the screws and rotate it enough to make it fully open. All the same for a cold or closed position. There's a range that the coil allows and there could be an issue within the choke itself. Just throwing that out there.

Igniion off (cold) it should be closed and at normal operating temp, it should be open. Improper adjustment will not allow the choke to find it's proper place, accordingly.

Timing is indeed important. Work on that first, then consider other actions.

.

.

tockit
08-11-2012, 11:36 PM
OK a little bit of an update, after a couple trips to the shops I have switch over to the Pertronix Ignitor EI. I had the hardest time trying to find a new set of points and decided to bit the bullit and just switch over. It started up great on the first time, but as soon as the choke become fully open it stalled out. I have re set the carb screws back in to a 1 1/2 turns in but can't seem to get it to idle below 1000 rpm. and it is still surging about 100 rpm forward.

I did check the PCV valve and it seems to be loose and fine. Although I did notice that there were no hose clamp holding it on and wonder if I could be getting some sort of leak there?

I still need to check timing and unfortunatly the parts stores around here don't loan them out. I have a friend coming by tomorrow with one so we can check it.

Is there anything else that I should be checking over since switching to EI?You won't regret the electronic ignition, especially in a marine environment.

You do know that you can adjust the idle speed on the passenger side of the carburetor with the screw that faces up, just inboard of your throttle linkage?

IIRC, screwing it out slows down the idle, and in increases the idle speed. I could have that backwards, but you'll figure it out quickly.

Normally this is done after your idle mixture is adjusted.

College Kid
08-12-2012, 12:03 AM
yep know about the idle speed, I am not that green, lol although I know it looks that way from this tread.

I can't drop it any more with out the engine stalling out. I am hoping the timing will be off and once re set it will cure the problem. After that I think we are out of options.

I should have an update by noon tomorrow.

Thanks again guys for all you advice and help.

thatsmrmastercraft
08-12-2012, 12:54 AM
Great to hear of the progress. You will enjoy the Pertronix upgrade. I had to adjust the timing slightly after I installed mine.

College Kid
08-12-2012, 11:50 AM
Does anyone have a "How to" for setting timing on the 351W? I did a bunch of searching can't seem to find a clean process?

College Kid
08-12-2012, 06:12 PM
Well I have some news,

The timing was set way advanced when we checked the timing, I wasn't able to find a for sure setting for timing but we I had read that it was 10 or 6. We tried both settings but niether was perfect. I have it set at 6 now and am holding around 1100 rpm. Can't seem to get it drop below with out stalling out. This is running with the 1 1/2 to 2 turns off on the carb tuning.

Any thoughts on if it should be 8 or 10 for timing? Or where to look next for issues. I thinking I should get it to the lake and see if it drops the rpm's to a resonable level when in the water, or is there something else I should look at before?

tockit
08-12-2012, 09:37 PM
Does anyone have a "How to" for setting timing on the 351W? I did a bunch of searching can't seem to find a clean process?
What year is your boat?
It's probably 10 BTDC, but if you're having this much trouble keeping it from stalling, the timing isn't whats causing your issue.
Sounds like a carburetor/fuel related issue.
It idle without stalling anywhere between 6 to 10 BTDC if everything else is correct.
You've got other problems...

College Kid
08-12-2012, 11:22 PM
Boat is a 92 Prostar 190,

I am thinking fuel air mix is the issue as well. As we have pretty much run out of other options. I have a friend who is good with carbs for the street stopping by later this week so we'll see if we tune it in a little better.

I'll keep you all posted.

tockit
08-13-2012, 10:52 AM
Boat is a 92 Prostar 190,

I am thinking fuel air mix is the issue as well. As we have pretty much run out of other options. I have a friend who is good with carbs for the street stopping by later this week so we'll see if we tune it in a little better.

I'll keep you all posted.
Engine timing is for you boat is 10 BTDC.

Just guessing, which is all we can do at this point, your carburetor either has a vacuum leak somewhere or possibly a clogged orifice inside the carburetor, etc.
Quite honestly, it could be a dozen different things.

Was this carburetor the PO installed a new carburetor?

Have you checked the fuel pressure going to the carburetor? It should be around 7psi.

Are you sure the fuel's good? Not contaminated with water, old, etc?


Here's some information on the 4160 carb. Your's probably won't have the fuel level adjusting nut on the primary bowl:


http://www.holley.com/data/Products/Technical/199R8108-2.pdf

http://www.musiccityrodshop.com/holpdf/4150.pdf

thatsmrmastercraft
08-13-2012, 11:38 AM
Agreeing with tockit that it doesn't sound like a timing issue. I would try a few more simple carb related things:

With the engine running at whatever speed it will idle, take a large rag and hold it over the top of the carb and see if this will kill the engine.

Remove the idle mixture screws and spray some carb cleaner in to clear the passages. It doesn't sound as though the idle circuit is providing enough fuel.

sxerob
08-13-2012, 04:14 PM
Looking forward to seeing the outcome of this one. Having similar issues on my craft. Thanks for all the updates!

College Kid
08-14-2012, 11:52 PM
So I have some news and some more questions.

Friends brother came over tonight and we fixed up the timing and started playing with a couple of things. At first we couldn't even seem to get it started but finally did after blowing some fairly large flames out the top........(never really realized how much those flame arrestors do).

So long story short it was a vacuum leak!!!!!!!!

The funny part that I can't figure out is why we didn't come up with this and it has made me think that maybe I have the wrong spacer between the block and the carb.

The leak was not so much of a leak but a nipple that was left wide open. Just under the intake to the carb for the PCV. It is about 3/8 wide and sticks out about 1/2 inch. I 'll try and grab a picture to update the thread later. Does everyone have these? or is this something from a street engine that found it's way onto mine? More importantly if you do have it what do you use to cap it? For now we have a heater hose with a bolt stuck in hose clamped together and it's running like a champ!!!!

Now for the bad news and I think I will start a new thread just to keep this on topic. but when we were starting it up the transmission wouldn't get into neutral, the shifter was in nuetral position, but it turnover and run!!!!! I have noticed some play in the shifter cable and will be replacing to start with but I am also thinking something might be wrong at the shift, as I thought it shouldn't be able to start with the trans engaged????

Does anyone know the best place to get the linkage? Is it a specific part for my year? or will I be able to just re run the cable and re use the ends I have?


after a little research I have figured out I have this plate that propbably was on the engine before the PO installed the 4160.

http://www.skidim.com/prodinfo.asp?number=R062075

and mounted the PCV to the new carb but didn't cap off the port.......

What is everyone's thoughts on best way to do this, or is there a different spacer I should get?

thatsmrmastercraft
08-15-2012, 01:33 AM
That is the correct spacer. Makes for a heck of a vacuum leak when it is open. :D might run a little better now. Oh, and if you haven't already set your mixture screws to about the magical 1 1/2 turns out, now is the time to do so.

As far as the prop turning, it will turn some while in neutral. Are you sure that this isn't what is happening? If not, there is some adjustment in the throttle assembly if need be. Neutral lock-out, if adjusted properly, should not let this happen. Neutral safety switch should also keep you from starting in gear.

Good progress. :toast:

College Kid
08-15-2012, 04:03 PM
Here is a picture of the two ports for PCV. Which does everyone suggest I use and which should I cap off? opps finger got in the way.

thatsmrmastercraft
08-15-2012, 04:31 PM
Here is a picture of the two ports for PCV. Which does everyone suggest I use and which should I cap off? opps finger got in the way.

If your thumb weren't there, I could tell if you have two base plates there. :rolleyes:

College Kid
08-15-2012, 04:36 PM
fine, I'll go take another. Lucky I am home playing "Mr. Mom" Today

thatsmrmastercraft
08-15-2012, 04:37 PM
While you are there, are there two spacers between the carb and intake?

College Kid
08-15-2012, 04:43 PM
Thoughts?

thatsmrmastercraft
08-15-2012, 05:00 PM
My 4160 does not have a vacuum port in the throttle body (the bottom casting). When you get a chance, take a pic of your carb from a couple sides and the top. I'm still not sure you have a marine carb.

College Kid
08-15-2012, 05:07 PM
I am pretty sure it's a marine carb, has J tubes. I am pretty sure it was bought through skidim.

thatsmrmastercraft
08-15-2012, 05:51 PM
Take a look at the plate between the carb and manifold. Is it just one plate, or are their two?

College Kid
08-15-2012, 06:08 PM
Two, a black one that was was original or looks that way, as well as the one that is under the new carb (alumiunm colour).

thatsmrmastercraft
08-15-2012, 06:24 PM
Great pics. Marine carb indeed. You can remove the spacer that isn't being used when you get around to it. New base gaskets when you do. Plugging it works for now. shouldn't make a difference which you keep.

College Kid
08-15-2012, 08:37 PM
hmmmm,

Anyone have a recommendation as to which to leave? the black one is about 1-1/2 deep and the other about 1/2 inch.

Does the spacer do anything or just offer a mounting point for the carb?

thatsmrmastercraft
08-16-2012, 01:01 AM
hmmmm,

Anyone have a recommendation as to which to leave? the black one is about 1-1/2 deep and the other about 1/2 inch.

Does the spacer do anything or just offer a mounting point for the carb?

The spacer insulates the carb from some of the heat from the engine. For example, if you removed them both, you would have to deal with vapor-lock. I guess I would keep the thicker spacer. When you remove them, give them both a good inspection.