[snapper69]

old girl back fired about 10 times this weekend only thing diffrent is ngk ird and spark arrester removed about 6 months ago any help would be appreciated

 

[BigCaveman]

running to lean maybe. I would think that taking out the spark arrester would have an effect on backpressure. Try a throttle chop test and see if you are rich or lean. Then try adjust air fuel mixture to compensate.

 

[excel88]

Put the spark arrestor back in, the run way better

 

[Yooperforeman]

I don't think the spark arrestor has anything to do with it...I've had mine out for over a year and there hasn't been any problems.I am going to put it back in 'cause I'm getting tired of the noise.

 

[excel88]

Without my spark arrestor i back fire when ever i gear down. Not enough back pressure

A spark plug certainly wouldnt change anything