no, they were hot. I had run it for a bit. and yep, i plan on doing that.

Thanks again for the help!

Ok. it is, in fact, not sparking when it does the stutter and die thing. I just went and rode around for a while with a spark plug in my pocket, since I can't seem to get it to do it when it's in my shop. jumped off and tested the spark and...whaddya know. no spark. let it sit for a few minutes....voila, spark again. rode it until it happened again, same thing. If I revved the throttle, I could get it to start and run on the rear cylinder randomly, but the front still wasn't sparking.

so this is the cycle: starts fine. ride it for a few minutes, stutter on one cylinder and die, no spark. let it sit for a few minutes, the spark comes back and it will run again. a few minutes later, it dies again. it seems to happen when the temp guage is around halfway.

definitely electrical. I really have no idea at this point other than a short in the harness or something having to do with the temp sensor.

not sure if possible but have you tried running it with temp sensor unplugged?

I have not. A very very very nice fellow is sending me a spare set of coils to test. I did find some info suggesting that coils and/or CDI failing only when hot is pretty common.

I would guess the cdi in this circumstance...

Hi There,


I'd check the pulse generator before replacing the other parts. Being that it is inside the engine, it experiences a greater change in temp than the external ignition units.
For what it's worth, I've replaced the connector behind the LHS radiator with a sealed one to keep the crap out of this connection.

thanks, i'lll look into that.

I think there's a method using a timing light to check this one in the manual.

not really. All you can do with the timing light is see if the timing is correct. if it's not, you can't adjust it, and it doesnt tell you if it's the sensor or the cdi or coils. there's another test in there to see if the sensor has the right voltage.

okie dokie, new update. an extraordinarily helpful forumite sent me a spare pair of coils to test on the bike. I put them on, went for a short test ride, all seemed well. put on my gear, went for a good 20 minute ride, all was well. come to a stop about a mile from my house, and it did the stutter and die thing again. ARGh. the weird thing is, it did it much milder than before. and it's been taking longer and longer for it to happen. it's almost making me think there's a clog in the carb somewhere that is working itself out.

finally got around to testing the pulse generator, which appears to be the issue. crossing fingers.

ok, so after a 25 day road trip through the rockies and a few other things that have kept me from the bike, I finally have the pulse generator on the way, have rebuilt the carbs yet again to put them back to the settings they were on when i got it, which worked nicely....so cross yr fingers for me, and stay tuned. Hopefully I can have it running again this weekend.

If you have not done so already, temporarily jumper out the kickstand switch to see if that is the problem. Or just buy a replacement on Ebay. I found a low mileage unit for $20.

I already did that, it wasn't the problem. thanks though.

OK, I admit that i did not read all the posts.
My kickstand switch would open when the exhaust heated it. Many times it occurred while waiting at a light.
I believe there are two contacts. one for the ECU, and one for the light.
Make sure you jump out the one to the ECU.
It's easiest to chop the cord and strip the wires.:)

edit. nope. still doesn't work.

oooook. turns out, it was actually a fueling issue. combo of two things: the petcock diaphragm was bad, and the vent tube was clogged, so the tank was getting a vaccuum lock and not letting any fuel out. I had checked the petcock and it seemed fine, but I went ahead and replaced the diaphragm anyway, and it quit doing the stutter and stall out thing. it's still a bit choppy right off of idle, I'm thinking the vaccuum vent isn't entirely cleared out, and/or whatever gunk was clogging it is also in the pilot jets.

Had the same issue recently. I thought it was a electrical malfunction but turned it was a clog fueling system. Good thing a pal of mine who works from 4 Wheel Online lend me a hand on finding the problem. It was just a 10 mins diagnosis and job for him.

so, I converted my petcock to a manual one and the problem seems to have disappeared entirely. crossing fingers.