2006 CFR250R. Bike is very hard to start. Seems to fire the first few kicks and then won't fire at all. After sitting for about 10 minutes, the same - wants to start the first couple of kicks but won't. Was able to get it running by bump starting - ran fine but them would not restart after shutting it off. Gas leaks from the carb bowl overflow when kicking the bike. No gas leaking when sitting still or running, just when kicking the kickstart. Removed and checked and cleaned the carb - replaced the needle (fuel) valve. Appeared to be clean, slight groove in the needle valve. Wiring looks good. Valves replaced and seats re-cut about 20 hours ago - clearance is good. Compression is good. Any known problems or similar experience with this?? Bike is 6 years old. Pretty good shape and well maintained. Thanks.