Why was it rebuilt, worn out or fried, or otherwise.?
Have you done a leak down test after assembly?
Dont be talked into changing the pilot jet the #32.5 stock jet is perfect for your application..
Is it flooding? Have you adjusted the float level.
How old is the gas in the tank?
Have you checked the pipe and air box for mice nests?
When you get it running please do a proper break in proceedure.