please can anyone help when my ty 80 gets warm it starts to missfire , running a 50-1 fuel mix new air cleaner, new main bearing to take all play out of flywheel , new points mixture screw set at 1 1/2 turns currently running on b6 ngk plug would changing to a softer plug help as the plug is all black and sooty when missfire happens thank you

Hi,have you checked the float height,if its wrong this will effect your running mixture.Should be 23mm+or- 1mm.Also could be worth checking the needle clip position, should be second from top.

Regards Andy.

Hi,have you checked the float height,if its wrong this will effect your running mixture.Should be 23mm+or- 1mm.Also could be worth checking the needle clip position, should be second from top.

Regards Andy.

thank you iwill check this cheers

Shouldn't the mixture screw be further out? Can't remember, thought it was nearer 3 turns?

Have you tried a better plug, iridium or similar. We used to 'pop' plugs fairly often (every few weeks) until upgrading plugs which then lasted for over a year until we changed bikes.

It sounds like the condensor is breaking down , fit a new condensor and check the faces of the points these may be pitted , if so replace them . the new points will need the protective coating cleaning off the faces with glass paper . the the ignition timing will need setting using a points meter to check that the point are closing correctly , and a dial gauge in the spark plug hole . the correct timing should be 1.8 mm.before top dead center .

Sam

sorry for delay in reply been working away thank you all for your help and will be in garage on sat go through all replies thanks again for all your help post findings soon