650/X-2 New motor in. Not running right.

[Thirdsetjeff]

Bought a brand new rebuilt 650. Dropped in easy. rebuilt the factory carb. new gas. fired up and thought we were good to go.. Fires up on 1 cylinder. Run it full or half choke to get running right. Once its on plane it ran good of a little bit. Then loss of power, which seems to be lack of fuel. Back off the throttle and hit it, it runs out for a little and dies again. Shut it down and go to fire it back up and it needs to be choked. From an idle it won't take off unless it is at least half choked. Stock carb and pipe. keihin carburetor 28mm.. Seems like its starving for fuel. Any thoughts??

 

[Vumad]

Doesn't matter what the problem is, get rid of that 28mm carb, then worry about the problem. That carb is way too small to get that motor to run right.

It only runs on choke because it is lean. Tune it, clean it, make sure the fuel system is free of junk.

 

[Thirdsetjeff]

Cleaned the tank, rebuilt the carb. Set it to were it was last time??