CR250 help.... No spark

[Strangler]

So, I'm far from a moron when it comes to this stuff, but I'm to the point that I need help.

97 CR 250

I rebuilt the entire engine for a guy because his cases were broken. The engine was delivered completely dissasembled because he was going to try and have the cases repaired. I assembled the engine using new cases, bearings, bla, bla, bla.

Once reinstalled in the frame, I had no spark. I walked through the test procedures for troubleshooting ignition components, beginning with his stator... it was found to be bad and a new one was ordered.

With the new stator installed, I again checked its resistance and output... it checked out but the bike still had no spark.

I continued by checking the resistance of both sides of the coil, per the manual... and found it to be faulty as well........

So, by know you know that I'm already wondering why a bike that was taken out of service because of broken cases also happens to have not one, but now two faulty ignition components......?? Didn't seem right to me, but I continued by purchasing a coil, wire and cap and installing them to find, guess what, no spark.

So the startor now checks out ok, the coil now checks out ok, The timing is correct, flywheel key is not sheared, etc and I still don't have spark.

So, I continue with the testing procedures, now finding the CDI to be faulty..... this is getting old.

I purchase a new CDI. I install it. No spark.

I have now verify'd timing and replaced every component in the igntion system with the exception of the kill switch, which I have unplugged (even though the test procedures tell me its fine).

I am at a complete loss. I have zero visable spark. When kickstarted, I have heard the bike pop a couple of times... not like a backfire, but like a single attempt to light when the kickstarter is all the way down and I am no longer spinning the engine, it it just spinning under flywheel momentum. The fact that it pops when I bottom out the kickstarter tells me that the timing is off, but the lack of any visable spark tells me there is still a weak link somewhere.

Sorry so long, but I'm at a loss and thought I'd throw it out there in case any of you notice something I may have missed.

-Scott

[chris1044]

Wow. I read this earlier this morning, and didn't post because I thought that maybe someone else would pipe up, and to be honest there really isn't much more I can think of that would help.

But, the first thing I would say to check is system grounds - you didn't mention whether or not the coil/CDI unit have good grounds to the frame. I'm sure you've already verified them, but it's little stuff like this we sometimes miss when dealing with projects from hell (from the sounds of it, thats what this sounds like ) It's not possible the spark is arcing somewhere else before the plug without you hearing/seeing it, is there? Possible fault in the plug wire by chance?

As you've stated, you've replaced virtually every component of the ignition system. The only other thing left to check is the rotor. I don't really know how it could fail other than loosing it's magnetic force, which is highly unlikely, if not impossible.......don't really know how you'd verify the amount of magnetic force it currently has either.

Beyond that, the only other thing I can honestly think of that would hinder the bike from having any spark would be some type of internal engine rotational resistance that is not allowing the rotor to move past the stator fast enough. Unlikely since you just rebuilt it, but again, it's something to think about....I've had this happen to me before, but it was because the mains were virtually seized. The bike would start if I pull started it at a very high speed, but I couldn't kick the thing over no matter how hard I tried.

The fact that it pops at the bottom of your kick is odd as well....while that would point to a timing issue, the ignition should have spark irregardless of its timing....

Again, the above is just stuff that comes to mind......either way, I'd be interested to know what the fix is when you figure it out

[tater8771]

just sell it to me im looking for a 250 frame for my 500 motor

[wiron]

It Pops When The Kick Starter Bottoms Out On The Frame, Sound Like A Groung Wire,

[Strangler]

Runs now. After replacing every component of the electrical system to no avail, I purchased a complete electrical system from Ebay off of a 97 that was being parted out. Replaced the stator/flywheel/CDI/regulator/rectifier/coil/kill switch with all of the Ebay parts and she started right up. I hate not finding a problem, and I'm sure there is just a broken wire somewhere, but I'm glad its running and I can get it out of my garage.