Prostar 351, stalls in reverse or when going in to gear.

[College Kid]

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]

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]

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]

Originally Posted by thatsmrmastercraft

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]

double post

[thatsmrmastercraft]

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]

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]

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]

Yup, those are points in there.

[College Kid]

Thanks, guess I'll add electronic ignition to my winer project list.