'03 450R running rough - need suggestions
Posted 10 May 2012 - 05:21 PM
Posted 10 May 2012 - 07:29 PM
Crap. I was careful to reassemble it the same way it was installed, but the bike came to me in poor running condition so maybe it was already like that.
Thanks, I'll check it in the morning.
Posted 12 May 2012 - 11:40 AM
Posted 12 May 2012 - 01:26 PM
Id douche the carb really well (clear with compressed air) and start over with the jetting at stock settings. Make sure all the vent lines are clear. Check the hotstart cable and make sure it's not seized with rust and that it seating. Happens all the time.
Is there anything done to the engine? High compression piston?
If it starts cold, but gets tougher when hot, it sounds rich. But I wouldn't rule out the intake valves either. They can go bad from a reshim in 5-8 hours of run time when the coating is completely gone. For a trail guy that could be one day of plunking around. Also the RPM isnt really the culprit. Its a combo of dirt, powdered metal seats and the coating coming off that kills the valve face.
You've got the carb out (if not, at least the tank is out) so at least cover the base and check the valves yourself. Ive seen them do weird shit when the lash gets down to .002".