Originally Posted by DoWhatsBest
I read on another blog page that a guy changed his carb jets from the standard f40 jet which is a number 40 to a F25LA jet and the problem went away.
Richiel says that he has a 40 Yamaha. Which is a two stroke model.
The carburetor mod wherein bigger jets are used applies to a four stroke F40 model.
And by the way, you are replying to a four year old post.