rider413 Posted April 6, 2010 I have had a 2008 YZ450f since it was new. The bike developed a killer bog while under throttle during the last ride. I pulled the carb and cleaned it. Pulled exhaust pipe. Disconnected the throttle position sensor, and kill switch. I also took the air filter completely off. All of these changes had no effect. The motor will start within one or two kicks. Then rev cleanly to almost 1/2 throttle. Then it falls on it's face so bad it will kill the motor. The jetting is the same as I have run since the last rebuild. Nothing found in the carb. The bike sounds way too rich but removing the air filter has no effect. Has anyone had ignition box or stator problems with these bikes? Share this post Link to post Share on other sites
grayracer513 My Ride Posted April 6, 2010 If it's really too rich, you might want to see if the main jet fell out. OTOH, you could be wrong, the bike could be lean due to a blockage in the jet. Share this post Link to post Share on other sites
davbrucas Posted April 6, 2010 Yup...I was gonna say that its a main jet issue. I would take the carb back apart and recheck. If it isnt that, then its likely electrical. Share this post Link to post Share on other sites
swatdoc Posted April 7, 2010 Damn your bike must be trick!!! But how did you get is 78 years early? Time machine? 👍 Share this post Link to post Share on other sites
cjxrider125 Posted April 7, 2010 it starts within 1 or 2 kicks, but is it harder to kick over? Share this post Link to post Share on other sites
davbrucas Posted April 7, 2010 Spark issue...replace stator. Share this post Link to post Share on other sites
Tim1018 Posted April 7, 2010 Damn your bike must be trick!!! But how did you get is 78 years early? Time machine? 👍 And their still using carbs. That disappoints me. Share this post Link to post Share on other sites
