2000 Yamaha 40hp fuel pump?

[seamule1]

I have a 2000 40hp 4 stroke. 40tlry. Anyway I launched today, started fine, idled great, slight hesitation on take off, continued at half throttle, smooth, then died. Could not restart. Tilted the engine up and it started but died when lowered into water. Could not restart. Last year I had the carbs rebuilt by a dealer, who replaced all the fuel lines,primer bulb, water seperator filter, and inline filter. Ran great last year. The motor has about 30 hours run time on it. Think it might be a fuel pump? Any help welcome!

 

[rodbolt]

Re: 2000 Yamaha 40hp fuel pump?

how much time passed between the last time it ran well and this time?
carbs will varnish up quickly, even quicker if fuel stabilizer isnt used,
I have a few customers that dont get it so I have done the carbs every spring for almost 20 years .
test spark, test compression and go fix the fuel system, I really doubt you will see a pump issue as when you prime it, it simply bypasses the pump and fills the carbs.

 

[seamule1]

Re: 2000 Yamaha 40hp fuel pump?

Thanks Rodbolt,
I agree. I was out looking at the pump and disconnected the fuel "in" line and pumped the fuel into a glass jar. Sure enough, water. I had just filled it up less than a week ago but during that time we had a storm dump about 3" of rain and I left the vent cap open. Shame on me. I hope this fixes it. But here is the kicker....I drained each carb bowl to get the nasty fuel out and snaped the bottom drain bolt off in the bowl ! I guess while I'm taking the carbs off to fix the bolt I might as well rebuild them. Thanks again!