problems all around

[mismatchtrike]

84 200s: runs for 5 minutes then no spark, half hour later sparks for the first two pulls then nothing.
a day later the same thing. been all over the wiring and seems to be clean and intact.

84 autox: runs good at 1/4 throttle but under hard acceleration it cuts out bad, I thought it was only in a wheelie but its any time I mash the gas it has a pro circut silencer for a muffler and currently no air filter (making one currently) Does anybody think it would need a bigger jet? and if so is this hard to do
and what size?


Thanks in advance, hair is almost all pulled out lol

[Grizzlypeg]

Electronic components can heat up and become intermittant. Coils, pickups, possibly CDI units could all have this sort of fault where they cut out once warm. You could try measuring the resistance of the ignition coil, before and after the problem, and see if it suddenly becomes high or open. You could also try applying some mild heat to the coil with a hair dryer and seeing if that brings on the problem, or cooling it with an ice pack and seeing if that restores it to function.

If the CDI unit and pickup work properly, they should be sending a pulse to the coil as the engine turns over. Perhaps you can find the pulse with a multimeter and moniter whether it still occurs when the fault comes up. Take a look at the factory manual and color coding of wires to see the possibilities.

[Yamaha_Rules69]

I had a similar problem on a 185s, in my situation, it was the CDI. Luckily for me, I had spare parts to try to see what the problem was. I would start by checking the wiring, and especially kill switch. I have seen this many times at the switch, if you move it back and forth, and try to start it, then it has spark. As for the other one cutting out, it sounds a lot like a carb issue. Have you taken the plug out to see what it looks like? Black = rich, White = lean, and cardboard brown=perfect jetting. Also, trying a new plug on either machine could be a good starting point. Good luck!