I helped a friend rebuild the top end of his '88 Warrior last week. It was still running good when we pulled it down, it just needed freshening up. We installed a new Shindy piston & rings (.20 over I think), new topend gaskets, and a freshly bored cylinder. After the rebuild, the engine fired right up and runs great with plenty of power and doesn't smoke. The problem is, now after the engine warms up and you start going good (like going through the gears), when you let off the throttle (to go around a turn or stop) the engine cuts off. If you roll to a stop it will start right back up within 30 seconds and do the same thing all over again at the next turn. It seems to run fine unless you let off of the gas. We took the pilot and main jets out and blew them out and checked the needle/slide as well as the float assembly. Everything seemed fine and we didn't find any trash in the carb at all. The bike is all stock. Any ideas on what is going on?

 

I'm not sure but i think there is a idle circuit in the carb that could plugged causing it to go real lean on deceleration