As far as keeping the carb clean, and the motor as well, we've had some great success with Seafoam. Just dump it in the tank every month or so. Rotaries absolutely love the stuff.

 

I use seafoam, but the jets still had buildup. In fact used it about a week before I went to Robert. Carb was pretty gummed up still. we have to have 10% ethanol by law here in oregon. maybe the the carb was to far blocked for the seafoam to do its job.