Hi, I have a 1991 cbr600f f2, it seems to have a weak spark, and will always fire on cylinder 3, sometimes not on 1 and 2, sometimes not on 1 an 4. I have replaced the battery, coils, ht leads. Could the pickup coil or cdi cause this sort of intermittent fault. It has fuel and compression, Thanks

 

check your battery for charging, low voltage can cause a weak spark. Test both voltage regulator and stator .Coils dont usually fail. I had a similiar problem, I had a couple of bad wire connections from voltage regulator and and stator connectors. eliminate each one of those items, that should fix your problem. it could be one of those causing a weak spark. Get a manual if you dont have one.

 

Rinferno, thank you for your advice, I will check the things your suggest and report pack

 

No problem, let me know what you find.