My ty 250 85 or 86 model seems to soot up it's plug after about 20 min of rideing, im am in the process of renovating it and have done the main bearings and seals, decoked and repacked the exshaust, replaced the reeds and rejetted the tk carb to 38 pilot 145 main and set the float height to 25mm. I have just checked the resistansis of the ignition according to the manual and have found that the coil was quiet a bit off wot it should be, so my question is could it be the coil that is causing the sooting up, i dont want to just buy a new one if there is no chance that this could be the problem.

Thanks Nick

Gday, sooty plugs indicate rich mixture. Dry and Black is fuel, wet-looking and black is oil. Which is yours?

Cheers,

Stork

Hi there

Thanks for the reply, the plug looks black and sooty but is not particularly wet, you can wipe the soot off with a cloth but it has ussualy wrecked the plug by then, im not sure if a poor spark at low revs would result in this, i think i shall replace the coil, having tested with a multimeter the resistance is way too high i think there is a break in the wire just hoping it cures it as im nearly at a loss with this problem having tryed every think i can think of with the carb.

Cheers Nick

Put a new coil and plug cap on tonight and started up second kick, after 20 min riding the plug was very slightly oily but with no soot, i still think it is a bit rich but hopefully will be cured with a little fine tuning, sparks very well now so hopefully the plug wont foul.

Nick