yamaha 40 running problem....

[maxfli981]

Hi guys,
My Yamaha 40 2 stroke starts no problem,but it runs lumpy and misses .I have checked for a spark on all cylinders...all ok,pulled and cleaned the whole fuel system,i'm getting a lot of carbon build up on each plug.It seems like a fuel problem to me ,but i'm not sure......any ideas.
Thanks

[99yam40]

post what your motor model is so others know what motor you have.

Have you checked on the prime start enrichment system if this motor has that?

Have you checked fuel pump for pin holes/tears?

[maxfli981]

I think it,s a 40HE.....i have tried everything ...still no luck

[99yam40]

I think it,s a 40HE.....i have tried everything ...still no luck

Sorry, but that tells me nothing about what the motor is(2 or 3 cylinder) premix or oil injected, choke or prime start, etc.
Or what you have done to it

[maxfli981]

sorry,its a 2 stroke,3 cylinder premix with a manual choke.I have cleaned the plugs,checked that i have a spark on all cylinders,cleaned the carbs,checked and cleaned the fuel pump and filter......im running out of ideas...