HELP---1990 bite the dust!!

[cicone]

HELP---1990 bites the dust!!

Was enjoying a nice ride yesterday with GatorKDX, when suddenly my bike just shut down. Seemed like someone pressed the kill switch. There was no surging or indication of lean or seizure. The bike had to sit for a while, then would restart on run for 30 seconds or so---did this about 4 times---even after putting in a new plug---before hanging it up. Got it home and checked carb, reeds, air filter and petcock/fuel flow. All looks in good order. Started her up--first kick--idled fine and rode down the street, died and pushed it home. Now I'm thinking it's an electrical issue. I installed an electrex stator coil around 6 months ago. Do you think it went bad on me? Hoping it didn't fry my CDI?? Maybe the primary coil??
Perhaps a short in the kill switch?? Thinking I'll disconnect the kill switch and see if it's that simple. Thanks,
Jay :ugg:

 

[Colorado Mike]

sounds more to me like the carb is going dry for some reason. Could be a clogged fuel filter that flows just enough to fill the bowl over time, but not enough to keep it from starving out. Could also be something goofey with the floats or needle valve. If you have the luxury of having a friend with the same carb, try swapping to see if the problem moves. Also, some tanks have a filter in the pick-up tube that goes to the petcock. See if yours does.

HTH,
Mike.

 

[cicone]

Drained the tank before checking the petcock---gas streamed out just fine. I would think if there was lack of fuel, the bike would rev out of control---just like what happens when you run out of fuel and have to switch to reserve. Almost seems like it's getting to much fuel and drowning the motor...but strangely the carb is not peeing and it has a new float from about 9 months ago.

 

[gn83tm]

I think I'd take another spark plug with me and when the bike stops I'd plug it into the coil wire and rest it on the head while I kicked it over to check for spark. This would narrow it down to electrical or fuel although my bet would be on electrical from what you've described. If it's electrical, follow the procedures in the manual for testing the individual components. Fredette would be a good source of used components if you can narrow it down. Hope you get it going (without having to spend a ton)!

 

[cicone]

Talked to Fredette today and he seems to agree the problem is likely electrical in nature. Says KDX CDI's rarely go bad. Called Electrex and they're sending me a replacement C31 stator coil for the one I bought 6 months ago and should update me later in the week on the status of the new rewinds---been waiting for 2 months now. Ritzo hopes to have them soon and Fredette is interested in dyno-ing them. Luckily, I get to seat-o-the-pants test them first! :laugh: Any thoughts, CC??Wib?Jag?Bump

 

[canyncarvr]

There are known problems with Electrex coils...timing changes and stuff.

Checking the spark with a plug hanging off to the side is a good place to start if you think it's spark. Remember the plug has to be grounded to do that (like gn already said). ...and holding it isn't always a good idea. If you are going to hold it, hold it good and tight to ground. Let it get a bit loose and it'll bite!

That would resolve the spark issue sorta. Because a plug fires in atmospheric pressure doesn't mean it will under compression pressures. It should be a nice fat blue spark.

Lack of fuel won't generally act like a kill switch. Generally it will surge or miss a bit before it completely quits. Checking the petcock does just that. Just because there is fuel 'streaming' out of the hose to the carb doesn't mean there is any fuel getting INTO the carb. Take the plug out of the bowl to see that part.

Did you solder the new coil in? In any case, check the grounds of the CDI and the coil...and any connections you made. A poor connection means resistance, resistance means heat, heat means failure. Then it cools off and you have your (poor) connection back.

Unplug everything on the CDI and make sure those connections are good. If you have the ground to the frame (as opposed as thru a connector as the 'H' models due in an oem config), take off that and any other ground and clean it up. Put it back together with some anti-oxident grease (like Noalox).

Good luck!