QuestionI have a Roybi model BC30 line trimmer. The problem I'm having is that after starting it and letting it warm up a bit, it refuses to rev up. When pressing the throttle controller to it's maximum position, the engine will rev up only partially to a steady RPM, which is too slow for even the clutch to engage completely. The trimmer line spins so slowly that it doesn't even have enough power to trim very well.
I removed the carburetor and blew it out with air after disassembling it, then reassembled it, reinstalled it, then tried running the trimmer, again, but it still reacts the same way. I don't have an exploded view of the carburetor so I can't disassemble it completely.
When disassembling the carburetor, I removed the diaphragm and priming bulb and blew out all the passages I could find. I also used some carburetor cleaner to try and "wash" out the passages. I checked the diaphragm and that seems to be OK.
It seems like it engine has an RPM limiter, which I know it doesn't. Any suggestions on what else I might check? This unit is about three years old.
AnswerLook Closely at your muffler, there is a spark arrester screen that is held in with a screw near the exhaust outlet. Remove the screen and try it, it should rev up to full speed now. Clean the screen with carb cleaner and a wire brush.
This is caused by using improper oil/fuel mix. (too much oil in the fuel) Some people believe that if a little is good a lot is better! LOL
Let me know if this takes care of your problem.
Dave
