Im posting this for a friend. He has a 05, or 06 LTR450. Its an awesome quad. Recently it began running badly. Hard starting and backfireing thru the exhaust. He went thru replaced the fuel filters, replaced the air filter with a K&N, new Stock exhaust, clutches, oil change, and I think thats about it. When he put it back together and went to fire it, all it would do was crank, sound like it was about to hit and run then back to just cranking. It would do all that for a few moments then POW shoot a large flame out the tail pipe. He then removed the fuel injection throttle body and found it full of carbon so he cleaned it out. Reinstalled it same scenerio when cranking except with a lil throttle it would pick up and almost run. We flipped the choke on, cranked for a few moments with 1/4 throttle and it finally picked up and ran. Still back fires thru the exhaust when running, and when you go to start it, its very hard to start. Anybody have any suggestions to try out or look into?

-Mark

 

I suggest going on ltr450hq.com they have a lot more support on the 450.

 

ok thanks