I have an 03 eiger that has been giving me problems for the last year. It is very hard to start when cold, after it does warm up it pops/backfires through the back of the carb. It does not have a constant idle as it revs up and down slowly. While riding it it does ok if while giving it constant throttle. When I turn it off after riding it, it seems to have built up pressure and backfires, or whatever you want to call it, it goes whoop!!! through the exhaust immediately when its turned off. I have throughly cleaned the carb twice and this did not help, new plug also. It has 750 miles on it. Not sure if this is a timing problem or valves need to be adjusted. Any advised would be appreciated.

 

i have the same problem. it dont worry bout it to much its just a very cold natured motor
ive put a jet kit in and that helped some.
if i run it in like 70 degree weather it runs like a totally different motor opposed to colder weather. i have about 600 miles on mine. i am thinking about adjusting the valves.

 

also the whoop in the exhaust? mine usually comes anywhere from 3-60 seconds after i have shut mine off. it sorta like a deep baloop. and everybody asks did your quad fart? haah but yeah i jus figured it was sort of motor decompression stroke??