yzf250 questions

[redracing88]

ok i just got a yzf250 dirtbike yamaha it wont idle and whenever i let off the gas it just backfires like crazy but when givin her gas she takes off like crazy it has a quickshot device on the bottom of the carb and also has a high compression piston in. its an o4 i was wondering if the pipe is out of packing or something causing it to do so but im not sure.

anything you might think it could be let me know

[GPracer2500]

Sounds like the pilot circuit is either clogged, too lean, or there is an intake air leak.

Start by removing the carb, disassembling it, and cleaning it thoroughly. Clean out all passages with carb cleaner and compressed air. Pay particular attention to the pilot circuit.

[redracing88]

thank you!!!