need help

CECAVCSAC

Recruit
Joined
Jun 21, 2008
Messages
3
Please Help,
I have a 2000 Johnson V4 outboard motor. Motor has a problem with starting and cutting off, it doesn't matter if it is hot or cold. Motor starts then cuts off , I have to choke the motor several times then work the throttle back and forth to get the motor to run. Already checked carbs, spark, and compression. Spark jumps 7/16 to1/2 inch in open air, compression tested hot and cold, left cold checked 118 psi top & bottom, right cold 120 psi top & bottom, hot 150 psi right & left side. Ran motor in yard on flush kit motor runs fine. Put in the lake it will not start correctly. It seems that the motor is not picking up the fuel. Here is the model number J90PLSIF Please help
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: need help

Runs fine on the hose at home but fails once in the water.

Usually thats a clear sign of a problem in the idle circuits of the carbs, dirty jets and/or dirty air bleeds. Fails to flow the increased amount once in the water.
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: need help

Totally agree with Charlie, those carbs need to be thoroughally bathed and rebuilt and blown out with compressed air. Pay attention to the jets as stated. Let us know if you need help in getting them out.
 

CECAVCSAC

Recruit
Joined
Jun 21, 2008
Messages
3
Re: need help

Still need help,
I have already rebuilt the carbs and the jets are clean as a pen every time I take them out. What else could be the problem.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: need help

What spark plugs are you using?

BTW - that's a 2001 model.
 

CECAVCSAC

Recruit
Joined
Jun 21, 2008
Messages
3
Re: need help

It has the correct spark plugs( Champion QL78YC) in it. I don't know what else to do. I've owned boat motors for 15 years this ones the only one thats ever giving me any trouble.
 
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