Aloha, I know this may be very simple and already known, but here is a carb tip. I was experiencing 4 stroking and lumpy running at low rpm's with my Oko carb. I stretched the spring on the choke rod to make the spring much stronger and now it runs great. I think the choke seal is not tight when the engine is vibrating and causes flooding and is most noticable when running at low rpm.
Too much spring tension may damage the seal more, though.
frank
Too much spring tension may damage the seal more, though.
frank