35 Johnson runs rough while accelerating

[johnsonjetprop]

I'm helping a friend work on a Johnson 35 model# 35R77H with a jet prop. It idles great but under acceleration it runs really rough and its topend is sluggish, except for two spots when it runs like a million bucks at about quarter and half throttle. any ideas would be greatly appretiated.

 

[moyster]

Re: 35 Johnson runs rough while accelerating

Try adjusting the carb while it is running and see if that helps. My 33HP was acting similar but adjusting the high speed smoothed it out. This is a good place to start.