1985 40HP Carb Tuning or other issue?

cortlillard

Cadet
Joined
Jul 17, 2012
Messages
7
Hey all. I have a 1985 2 stroke Yamaha 40ESK, and it is not able to hit full RPMs. I have fixed a lot of issues, cleaning out all of the sand/salt from the water cooling manifold, fixing a short in the wiring, and cleaning the carbs. There is now spark on all 3 cylinders, and the compression is good.

I am not entirely sure how to get the correct fuel to air ratio on the carbs. It is a 3 cylinder, and originally had an oil system, but was removed by the last owner. Now, we just add oil to the gas at a 50:1 ratio.

I have reason to believe that the tuning on the carbs may be wrong after cleaning them, and that is why i am not able to hit full rpms. I have browsed the forums, but did not find anything with removing the onboard oil system.

I set all of them the same, screwing the tuning screw all of the way in, and backing out 2 revolutions. I am not sure if this is proper.

Thanks for the help!
 
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