HI,HAVE 05 4RT,Bike has developed a missfire when engine gets up to operating temp.Have changed plug several times no qure anyboby any suggestions please.

Try a new plug cap, are you letting it warm up with no throttle untill the fan kicks in?

bike allowed to warm up,problem usualy starts after 15-20 min of riding,on removing plug it is black,runs 15-20 min again on new plug before misfire returns,will try new plug cap and lead thanks.

a loose exhaust flange (at the cylinder) can cause a backfire

Gday, does the black plug look dry or wet?

Cheers,

Stork

Two more things can cause this problem i have come across when air filter gets resrected & one were the tell tall is when it kicks back (TIGHT TAPPETS)

HI,HAVE 05 4RT,Bike has developed a missfire when engine gets up to operating temp.Have changed plug several times no qure anyboby any suggestions please.

Did you get it sorted?

Problem seems to have been solved,fitted plug lead,new cap,and new coil.thanks for everyone`s help.

Also worth checking on the older 4rts are the 2 wires, terminals and earth on the ht coil. These can get pretty corroded.

I had a minor miss when on tick over. Never stopped, just missed a beat now and again. Stripped and cleaned kill button problem sorted.

Also worth checking on the older 4rts are the 2 wires, terminals and earth on the ht coil. These can get pretty corroded.

Too true Sunt, David's 07 bike had an intermittent cutting prior to the SSDT, which was only cured when the wiring harness was replaced (thanks Munch for the advice on that point!) It was the wires leading into the coil that were at fault. Wiring harness is not expensive around