87 trx250x no spark-- ready for target practice

[Gjpctech]

Alright guys, as promised in my introduction mesasge, here's the rundown on my 250x. Maybe you can offer some suggestions that I haven't tried yet. Sorry for the long post!!

1) I have the manual and have been following troubleshooting steps and checking resistance with my OHM meter to matching specs.

2) I had the bike up and running just fine. Rode it a few times up and down the driveway. Thet last time I had spark, I was simply adjusting the idle between the handle bar throttle cable and idle knob on the carb. Then I shut 'er off with the kill switch and it's been no spark ever since.

I started with the free/cheap things... I pulled off the wiring harness and ohmed out all the components. Then, I did a continuity test between the CDI connector and the other end of each wire. I even cut off the ground ring and replaced it with a better lead. I changed the oil, replaced the spark plug, tested continuity at the kill switch and at the key. Bypassed the key and even the reverse lockout sensor. No spark.

I OHM'ed everything out and it was all in spec. But on some of these Forum boards I read that the stator could test good, but still be bad, so I replaced it and the pulse rectifier, still no spark.

Next, the OHM on the ignition coil was low, so I replaced that. No spark.

Finally, I spent the $120 bucks for a new CDI box. Still nothing.

I just don't know what to try next. The only part I haven't replaced in the electrical system is the AC Regulator. There just isn't that much to these things.

All my spark tests have been with a new plug, with a lead from the tip of the plug to a wire that is grounded to the block. That way, I can see if it sparks while I'm kicking it over and it doesn't slide off the metal fins.

There's a couple things I was thinking for my next step: Rebuilding the wiring harness, adjusting the valves and replacing the flywheel since the stator is new.

I would love to hear any other suggestions. Thanks for your help!

[hillbillystan]

You said u used the kill switch when I hooked u my teather kill wisch I had that problem then I tour the hand swicth apart and the wire was loss in there swicth

[Here 2 help]

The 250X has a pretty simple ignition system. It consists of the alternator, CDI unit and the coil. You kill the ignition by connecting the black with white tracer wire to ground (the green wire or frame).
Start by unplugging the blk/wht from the CDI unit. That should eliminate all "kill" connections. The regulator has nothing to do with getting spark.
In a nutshell, the black/red wire from the stator charges the CDI box, the black/yellow wire from the CDI box goes to the coil, the green/white wire on the CDI box goes to ground, the blue/yellow wire on the CDI box goes to the pulse generator (tells it when to fire) and the grey wire on the CDI box goes to the reverse switch to limit reverse speed.
My guess is (since it was running and you shut it off and then never got spark again) the flywheel was not properly tight and it sheared the flywheel key when the engine stopped. If the key is good, then - you have lost ground somewhere - the black/white wire is shorted to ground somewhere - a wire is connected to a wrong wire - there is a bad connection on the wiring or the wiring harness is defective (wire shorted to another wire inside the wrap). It is unlikely the flywheel is bad, but it can happen. In 30 years of wrenching, I found a bad flywheel on a Yamaha Timberwolf. The magnet got weak. Other than that, the only flywheels that I ever replaced were damaged in a crash or improper servicing (hit with a hammer in an attempt to remove) or were damaged during catastrophic engine failure.
Hope this helps. I might be able to post a pic of the wiring diagram.