Hi all. My '92 1200 sportster keeps killing it's spark plugs. This always happens when cold, just after start up. It starts ok on choke then starts back-firing before going dead on 1 cylinder. I then check the plugs to find out that 1 has died. It can happen on either cylinder. They are Accel plugs. The bike was running rich but the mixture is now ok. It's a 1200 conversion with Wiesco pistons. Any help would be much appreciated.

 

Can you post a pic of the plugs when this happens.

 

Have you tried a different brand plug?

 

is ur plugs gap set at .40

 

Sounds like either too cold of a plug or bad ignition wires. The original plug are made by champion. I had the same problem on my 64. I tried accel, autolite, AC Delco and always fouled plugs after a few trips. Went back to champions and never had a problem after that.

 

I think so too.