Hi all, repairing a 04.5 500HO. Bike sat for a bit, motor was full of fuel. Did the carb thing, new needle and seat, starts and idles perfectly. The problem is when running, and you get to 3000RPM, bike spits and sputters. Once you get past 3000RPM, it pulls like a freight train. Doing this in forward and reverse, even with the override button pushed it. Other than this hiccup at 3000RPM, bike is working perfect. Any thoughts?

 

First thing you could play with the needle position and see if that helps if it's more of a mid range problem.If that doesn't help, the BST40 float is a funky set up as you've seen.Might recheck the float level along with glancing over this carb similar to yours but on a Ktm.Shows exactly on float settings along with other things you may have missed if it is the carb causing the problems. The BST-40 Bible - ADVrider