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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 15922
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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I have amercruiser 350..... It start but then revs up and

Customer Question

I have a*****mercruiser 350..... It start but then revs up and you can here it sucking in a lot of air then it dies.... What do you figure?
Submitted: 2 years ago.
Category: Boat
Expert:  Jason replied 2 years ago.
Hello my name is ***** ***** am I speaking with?
Can you tell if the sucking noise is coming from the throat of the carb? Is there a nipple on the back of it with a hose on it?
When did the engine last run, what is the story on it?
Customer: replied 2 years ago.
Everything is attached to carb. Noise coming from air intake everything is tight, had it running yesterday worked fine..... Was sorta having same problem a few weeks ago and it was also loosing power here and there but figured it was shitty fuel from dock..... I put engine boost and cleaner in fuel this time around
Expert:  Jason replied 2 years ago.
If you pull the air cleaner and start it, is the choke real tight, or are you able to push it open with your fingers?
Customer: replied 2 years ago.
When I have the throdle unhooked it opens easy
Expert:  Jason replied 2 years ago.
Look down the throat of the carb, and pump the throttle. Do you see 2 strong streams of fuel shoot out with each pump? Also, will the engine stay running if you keep pumping it?
Customer: replied 2 years ago.
It's fuel injected
Customer: replied 2 years ago.
Can't see anything...... And I tried starting it and hitting the throdle and it wouldn't die right away but revs would be up and down and alarm going off
Expert:  Jason replied 2 years ago.
Which is it, fuel injected or carb? In your initial question you wrote
" Checked carb and vaccume hoses". So I took that to mean it was carbureted.
Let me get the serial number on the engine, that way I can run it and see exactly what it is.
Customer: replied 2 years ago.
Expert:  Jason replied 2 years ago.
That is not the correct number. The number would be on a metal plate just above the starter motor.
Being this is a fuel injected engine it would have to get hooked up to a scan tool in order to figure out the issue. The best I can offer you here is a best educated guess. Would that be helpful, or do you need a more concrete answer?
Customer: replied 2 years ago.
Mechanic coming in the morning sorry for wasting your time
Customer: replied 2 years ago.
It was the fuel pump
Expert:  Jason replied 2 years ago.

Glad to hear you are up and running. Thanks for the follow up, I do like to hear the outcomes.

Happy boating!


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