85 Kx85 missfireing ...? Help please

Time before last my bike I was running great and then the next time I took it out It was running like crap it was also about 30° colder. Temp determines what will Run like. Have you had any temp change in your area!

Once I rode my RM in 34 degrees, don't think it ever ran better, until it spit a crank bearing. Now I don't ride it unless it's above 40 degrees, I could jet it for the last two weeks of each season, but I'm not inThe mood for that usually.
 
i used to see people stud up their mx bikes and bring them out to connors or finger lake and push them back to the truck after about 7-10 laps. you learn pretty fast to jet up, and if you are running something silly like 50-1 anything that you are probably going to go through rods and bearings by the hour. that said i probably have 1000 hours of happy ice and snow riding on two strokes. about a million snow machines can't be wrong. one of my friends has been riding his KTM 300 the last two winters, probably got 20 on it this winter already, as the trails have been pretty summer like with the low snow fall.

green and yellow always seem to be the first to get hauled home in the past, my worst luck being with my kx500.
 
you dont mention setting the float with cleaning. usually the only thing that cleaning will do to help an over rich condition if you think about it is that you may get debris off of the float needle and seat that will help it shutoff more fully. if yours still hasnt been set and set correctly with pieces that in good working order you may have it running even richer now than it was. but if you did replace the piston and rings it would probably run a little cleaner for a few hours, but it would still need the float set. you may be missing out on how important that is to a well tuned bike.
I didn't set the float no, I will take it off and do that :) however I think it's electrical :/ sounds electrical. It runs fine and on tick over sounds like someone's pressing the kill switch randomly now and then. Someone said could be stator plate ?? The coil looks fairly new .. I've only had the bike 2 weeks so. It sure what she's had but know the owner has stating issues. He was running 32ml of oil to 1l of petrol tho !
 
You skipped what I would call the most important step of a rich running bike. You may be right on the bike having an electrical problem, but the odds are so much greater that it is over fueling are SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO much greater. The symtom you describe is very much the same, especially if you are describing very low or higher rpm shutoffs. I bet that one has NEVER been set. bad floats are the source of at least half of the "great deals" I buy. I love them!!!!!!!!!!!!!!!!!!!!!!!

The stator is an easy check with a ten dollar multi meter and a pretty expensive fix if found bad. Do not short cut this time though, and check the resistance in the ignition coil, wire and cap.
 
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