787 fuel/carb issues...need help

[gcha1727]

My boat has the twin 787s. One motor starts/runs excellent. Other does not.

Heres what happens;

I can get the motor to start on the trailer but I almost always have to be using the choke. Even when the motor is warm. Once it runs it sometimes stays running but usually sputters and stalls. If I put it in forward and tthrottle up I can keep it running.

On the water its hard to start. When I do get it running, if I can throttle up past 4000 rpms it will stay running and run great.

Ive taken the carbs off a couple times now. Im not sure what to look for next. When I took them apart the gaskets and filters look good. All fuel passageways seem clear. I dont have a popoff tester so I cant check pressure inside.

Good compression, new plugs, Cut back plug wire ends, raves just cleaned.

Any ideas???

Thanks

 

[Phildoo]

What's the compression you have?.. Sounds like your overlooking something with fuel system

 

[gcha1727]

The compression test on the motor was close to 150 psi on both cylinders.

Yes, I agree that Im probably overlooking something in the fuel but havent been able to find it yet.

Is there anything in fuel circuit in particular that would only effect at the lower rpms?

 

[jhjesse]

JMO
Your boat has a fuel delivery problem.

Inline fuel filters replaced?
Internal filters replaced?
Accelerator pump diaphram replaced?
Needles and seats replaced? If so did you use the old springs or new ones?
Fuel pump diaphrams working properly? Possibly a pin hole or small tear.
Checked the pulse line for leaks?

 

[Phildoo]

Yea. Just go thru the fuel system again and I think you will find yor problem.