yamaha tripple only runs well with choke 1/4 closed

[chrisdoc0608]

Had problem with ski running like crap. Pulled carbs went through them cleaned and inspected everything, it was all good. Fixed air leak at manifold, all new gaskets and pressure test. Put carbs back on and reved up well on trailer. Today I backed it in the water and it will only run well at top end. I tried to tune low speed but couldnt get any change even from going 2 turns out all the way to 1/4 out. The only time I can get good throttle response is when i slightly close the choke, about 1/4 closed. Once the choke is closed slightly it runs great.... what am I missing? Also, when looking down the carbs with choke completely open, I really dont see fuel coming from the bombsites in the carbs, if i slightly close the choke I see plenty of fuel coming out... It appears that I am not getting enough pressure through the carbs to signal the fuel. All lines are in great shape, all internals look great, no holes in diaphragms, ect.... all three carbs are exhibiting same symptoms which leads me to believe it is not something inside of the carbs. Any help would be appreciated

 

[FlightPlanDan]

I don't know much about anything with three carbs......but if partially choking it is making it run, then you have a fuel delivery issue.
Or, a bad enough air leak that would take that much fuel to compensate for.
I'm assuming this is a couch. The on/off/res switches often go bad.

Take that switch out of the equation and see what happens.

 

[bllewis394]

id check the fuel tank check valve and the fuel filter.

 

[Matt_E]

id check the fuel tank check valve and the fuel filter.

Since the fuel from the choke circuit still comes from the same tank (and choking it makes it run better), I wouldn't start at the check valve & fuel filter.

I'd take the carbs apart and see if the internal filters are dirty.

 

[bllewis394]

Since the fuel from the choke circuit still comes from the same tank (and choking it makes it run better), I wouldn't start at the check valve & fuel filter.

I'd take the carbs apart and see if the internal filters are dirty.

yeah, but he said he already cleaned/inspected all the carbs, which would lead me to believe it was an issue common to all three.