View Full Version : X1 2001 chronic mis-fire at high revs

02-22-2009, 04:08 PM
After 5 months of untroubled X1 ownership my 2001 X1 has started to mis-fire very badly when approaching 4000rpm, its sweet below 4000rpm but go towards 4000rpm and the thing stutters like crazy all the way to the rev limiter. I tried to figure out if this is a problem when the bike gets really hot, but no - it happens very early on in the ride after a few minutes. It only started happening recently - I have made no recent mods - the bike came with a race ecm and pro series muffler but was running perfectly until recently. The problem doesnt seem to appear until I am a little way into the ride. Anyone got any ideas?

02-22-2009, 10:20 PM
Mine did something similar to that, running steady state 3-4k rpm she would studder or misfire, I fixed it by jetting it a little richer, and that solved the issue for me. I would also check the fuel filter and pump just in case.

02-28-2009, 08:21 PM
"Ophawk" may be right. It sounds like something to do with your fuel. I don't think the ecm is going bad but it is a possibility. If you don't already, run high grade fuel in your bike. None of that cheep crap! I'm a mechanic in the military and I work on my own bike and car, the cheep gas can start messing with **** after some time. Also check your spark plugs, wires, leaks in the fuel system. Work your way through the bike to eliminate one thing at a time. Hope this helps you..

04-10-2009, 04:37 AM
Solution was : the header temperature wire was twisted and bare wire exposed near head end so was shorting out