2452 GM 350 power issues-gctid818437

[kingfisher_11]

I have 1996 2452 Express with 350 engine that I just bought that is giving fits.

The engine starts and runs excellent until I get up to 8 MPH and it starts to loose power, sometimes stalls. I can run it all day at no wake speed and at approx 8 mph with no issues.

I changed out the water separator today. That did not look to bad, not much water in it..

This not a injected 350 CI engine, very clean and well taken care of.

Looking for suggestions that I can check into before I take it to a marine mechanic? I am quite handy if I know the problem.

Thanks

Bob

[Don77]

When was the last time it had a full tuneup? How many hours on engine?

I would start there, ck timing , compression etc.

Don

[Don77]

P.S.

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Don

[ekuehn]

Also check your fuel tank vent line it may be plugged. Ernie

[builderdude]

"ekuehn" post=818474 wrote:
Also check your fuel tank vent line it may be plugged. Ernie

+1

Try running it with the fuel cap removed to see if the issue goes away.

[Guest]

Did it ever go above 8mph since you had it? Exhaust water flappers installed wrong? Check fuel pressure?

[kingfisher_11]

[quote]"dilligaf" post=818541 wrote:
Did it ever go above 8mph since you had it? Exhaust water flappers installed wrong? Check fuel pressure?[/quote

]Yes I got it up to 12 mph when I first drove it.

[kingfisher_11]

"builderdude" post=818529 wrote:

"ekuehn" post=818474 wrote:
Also check your fuel tank vent line it may be plugged. Ernie

+1

Try running it with the fuel cap removed to see if the issue goes away.

I did that yesterday with no change in power

[kingfisher_11]

I pulled the filter at the carb, it had a couple of small pieces in it. Checked the lines to the tank and pulled the main tube i the tank, Have yet to take it out after these. I don't think these fixes will solve it.

I reved it at the dock while in Neutral, did it as high as I felt comfortable and it sounded good

[builderdude]

Your boat should do speeds around 40 mph at WOT. and cruise all day around 25 or so. Have you looked at the timing? If it's set correctly then I'd do a compression test next. What rpm are you getting?

[kingfisher_11]

Got it running, can't say exactly what one thing fixed it? I cleaned a very dirty arrestor, pulled filter at carb, pulled the tube going in tank and cleaned, tighten some clamps and cut a small piece off hose off where it connected to the gas tank.

Ran very good today during test run topped out around 40 and then I backed it off to 28-30 MPG and ran out about 18 miles.

[Ruffryder]

restricted fuel delivery ... now all good!

check the fuel pick up screen when you get a chance.

[builderdude]

Good to hear she's running properly, so there was gunk on the pick up tube in the fuel tank I'm guessing, like Joon pointed out she was starving for fuel.

[kingfisher_11]

I found a little gunk in the carb filter and the pickup looked good but I did blow it out. The former owner suggests I take the car off and check the float bowl. He has had to do that once and clean it in the 8 years he had it.