have an engine that sounds like doing the same here kaw fh480v-ds 20. someone had mention nearby could be a coil, as was acting up when it got hot but today i used it and it started from the get go. keep going back to thinking it;s fuel related but i'm no expert. gotta the valves this wk,they are over do per manual. not to mention larry's fix. btw looks like 2 different types of coils are on this engine, least price wise. had me curious why would they be different. if they are at that.