Backfiring ?

[liljhall09]

Ok well i just got my quad jetted, It has a full sparks big core , uni filter no outerwear, 180 main and 50 pilot. The quad backfires when letting off the gas ? Im guessing the jetting is good. Any other ideas ?

[dirtrider77]

the most common fix for this is adjusting the fuel/air screw (pilot screw) on the bottom of carb...if you turn it out more than 2.5 turns and it still hasnt quit, usually your pilot jet is off...

if it still backfires after messing with a few diff. pilot jets, and adjusting the pilot screw, then check the exhaust header and make sure the gasket is there...if not, get one and this should stop the backfiring

also make sure there are no leaks in your exhaust, the most common places are where the header bolts onto motor..and where the header and silencer meet

if none of the above fix the problem, it is probably time for a valve job, so check the valve clearances and go from there

good luck!!

[dirtrider77]

also, is your airbox lid off?? with your jetting specs, it should be, if not take it off

[liljhall09]

alright , ya the airbox lid is off ! and how can i tell if the gasket is there ?

[dirtrider77]

take the headpipe off, and look on the end of headpipe (where it goes into motor, and there should be a gasket there


....also take your carb off and take every plastic and rubber thing off of it, and take the bowl off and the top of carb of and let it soak in carb cleaner, and make sure to take the fuel filter out and clean it......mine used to backfire reallly really bad, and my carb was really dirty and the fuel filter had gobs of crap in it, after a good cleaning the backfiring was reduced 99%!!!

[liljhall09]

alright ill try all tht , thanks dirtrider77

[dirtrider77]

no prob

[liljhall09]

does anyone run a k+N with a sparks ?

[dirtrider77]

people run all kinds of air filters with all kinds of exhaust

doesnt really matter