Re: 18HP saga continues. Can’t get past 14mph and 3,900 RPM.

[billw]

I would take a close look at the throttle cam follower adjustment. Your carb throttle plate might be opening a bit too soon in relation to timing advance. 18s like to wear out the cam follower roller. This makes it so sometimes it’s adjusted right and other times, it’s not, based on the random clock position of the follower roller. Also take into account the wear in the linkage. The throttle plate itself should JUST be about to open when the roller lines up with the mark on the mag’s throttle cam.

Long live American manufacturing!