Hard to start after running for a while

dvan1901

Chief Petty Officer
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Mar 26, 2006
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503
I have a 4.3V6 (GM based) and when I initially put it in the water it will start right up. However, lately (last two times out) after I've been running it for a while (skiing and such) and then I go and anchor for a while, it is hard to start again (harder than when it is cold). I did some research on the site and found where it may be a gas vapor issue. Whenever I anchor, I let the engine idle for several minutes while I set the anchor and such which allows the engine to cool down a bit. Just wonder what the issue could be here; if it is still a vaporing issue, how do you fix it? It hasn't always done this so I'm a bit at a loss. Thanks!
 

Don S

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Aug 31, 2004
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62,321
Re: Hard to start after running for a while

When was the last time it had a full tuneup?
 

stronga

Cadet
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Jun 20, 2007
Messages
18
Re: Hard to start after running for a while

If you think it is a vapor lock you will either have to wrap the fuel line, or fuel pump with a heat resistant tape. I bought mine on line at JC Witney. Or worse case move the fuel line.

If you have not had a tune up in the last year or two I would guess from my own experiences that is your problem, at least bad plugs.
 

dvan1901

Chief Petty Officer
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Mar 26, 2006
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503
Re: Hard to start after running for a while

I had the engine rebuilt in the spring (new long block put in). It ran great for a few weeks and then just started to do this the last couple times out.
 

dvan1901

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Re: Hard to start after running for a while

Bumping...

Wondering if there is anything I can/should look at before I head out the next time. One thing I have wondered on this is, I've added some fuel/carb cleaner to the gas. Could this cause it to be running a bit too hot and cause this? Anything else to look at?
 

DayCruiser

Ensign
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Sep 24, 2004
Messages
953
Re: Hard to start after running for a while

Mine use to do this and it was the choke. The carb needed rebuilding too. But the merc carb choke is what caused the problem because it started right up when it sat for a day.
 

paulrfrancisco

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Oct 25, 2004
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341
Re: Hard to start after running for a while

What do you mean Hard to Start...

does it labor when cranking the starter?
does mean you have topump the gas?
does it mean you're flooded and have to go to WOT to get it tot start?

Please elaborate
 
Joined
Jul 2, 2007
Messages
53
Re: Hard to start after running for a while

dvan, I am having the exact same problem with mine. It happened to us once last season and once this season. Unfortunetly, I think I flooded it both times trying to start it and had to be towed in. The odd thing is that we can go out 3, 4 even 5 times and spend all day running it hard and it won't give us a bit of problems. Let me/us know what you figure out. I was going to start with a full tune up before next season and see what happens.
 

dvan1901

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Mar 26, 2006
Messages
503
Re: Hard to start after running for a while

paulrfrancisco,
By hard to start, it acts as if it is flooded, eventhough it had been sitting for an hour or so. If I run the boat, say for skiing or something, for a while then sit at anchor for a bit it can take several minutes to start. It's harder to start than it is when the boat is cold at the biggining of the day. That help?
 

paulrfrancisco

Petty Officer 1st Class
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Oct 25, 2004
Messages
341
Re: Hard to start after running for a while

Thats what I suspected... I actually have a similar problem. What I contribute it to is the carb leaking into the intake manifold.

When cold, it has leaked into the manifold and evaporated so when you start it you pump to close choke and crank... it fires up in a few seconds... but after warm and sitting for an hour or so..., its flooded. I have to WOT it and crank to start it...

I'd bet Carb issues...
 

Coors

Captain
Joined
Dec 8, 2006
Messages
3,367
Re: Hard to start after running for a while

Keep a new set of spark plugs in the boat.
Next time it does it, pull the plugs; if they are black or wet- too rich, or water.
 
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