Hi everyone.

I'm new to the nsr250 mc28 world.
I have read alot of the posts you guys have kindly provided.
I have one question as you can see from the title. I have rebuilt a 1994 nsr250 mc28 the bike will start fine and seems to rev fine but when I let go of the throttle the front cylinder stops firing and smoke roles out of the exhaust when it drop below 3k. My compression is 140-150. If anyone would be kind in shed some light on this would be greatly appreciated.

thanks