Been having a problem with our 50 for a while now. The carb gets plugged up with stuff and wont run. It revs up and down up and down. We take it in they clean the carb and it works but then it happens again. We have done this at least three times.
We use clear gas with staybill in it also. What can we do to stop this? Is there an aftermarket carb we could put on it or something?

FYI this is the 4-stroke.