I have browsed this site over the years, it is a great site, but I had to join to tap your knowledge on a scary situation. I run an 81 XT500 Yamaha motor in an ice racer here in Michigan. Standard hopped up XT motor, cam, piston, CLAMP ON AIR FILTER, UNI. Anyhow, the bike ran great all weekend until I went to start it one time. I did not really pay attention to the sight starting window and booted it. It backfired a bit and then proceeded to ignite the air filter assembly, crankcase breather and some of my wiring. Only some quick snow saved the whole machine!! I just finnished the bike, new tires, paint, etc. What can I do about this?? Will a standard K+N filter be more fire resistant than the UNI?? This could have been a real mess if the carb was leaking and it ignited the whole 2 gallons of race fuel in the tank!! I have heard about TWIN making a fireproof air filter, any suggestions?? Any info. would be greatly apreciated. Thank you.