Originally Posted by sledstorm1
Happened to my son's 250 xcf... one month of trying to figure out why it's misfiring...broken spark plug cap, arching at odd times, wet and just close enough to cylinder... ya never know
+1. This JUST happened to me with a BRAND new 500 EXC- I switched out the exhaust and it would back fire and stall. I spent all day trying to figure out what I could have done wrong- only .1 hours on the clock.
I was comparing the plug on that bike to another 500 EXC and my greasy hands exposed the crack in the procelain.