Another 250R sparking problem

[sunnyday]

so this 1985 - 250r was runnnung great , then the kickstarter stopped grabbing, so I went ahead and bought a 1988 kickstarter gear / shaft assembly. Now the kickstarter works perfect, but the damn thing stopped getting spark.

I tryed new plug, checked connections, etc...

when I kick it, the front headlight does flicker on...

and I will actually see a quick spark happen on the sparkplug, after many kicks, then it wont spark at all ...

does this sound like a specific bad part within the electrical system ?

Could it possibly be a broken keyway on the flywheel ? If that were the problem, would the headlight still flicker on everytime I kicked the kickstarter ?

[sunnyday]

I guess it couldnt be a broken keyway on the flywheel/ crank..because when I kick the kickstarter, the flywheel/stator and crank move in unison { I took the stator cover off} ..doesnt look like the flywheel is slipping at all.

[JJMF1979]

Could it possibly be the connection between the plug wire and the pug cap I had that problem before wasn't a 250r though but I imagine the setups are the same I took the plug cap off cut a little wire of the end and made sure there was a good connection

[RIDE-RED 250r]

You could have a bad/corroded pulse generator, bad CDI or coil if you plug wire and other ignition related wiring checks ok. If you can, swap out components one at a time with known working components.

With the stator, one side runs the ignition and the other goes to the voltage regulator to run the lighting. The service manual should give specs for testing components with a meter if you have them.

[sunnyday]

You could have a bad/corroded pulse generator, bad CDI or coil if you plug wire and other ignition related wiring checks ok. If you can, swap out components one at a time with known working components.

With the stator, one side runs the ignition and the other goes to the voltage regulator to run the lighting. The service manual should give specs for testing components with a meter if you have them.

but if the lights flicker on, then it wouldnt be a broken keyway..correct ? a broken keyway should result in the flywheel slipping and not creating any electrical output ?

[sunnyday]

Could it possibly be the connection between the plug wire and the pug cap I had that problem before wasn't a 250r though but I imagine the setups are the same I took the plug cap off cut a little wire of the end and made sure there was a good connection

ill check that tommorrow...

[atc300r]

With a broken flywheel key it would still spark and the light would still work.Usually when a keyway breaks it will wedge the flywheel and it will still turn.When it breaks it will throw the spark out of timing.

[RIDE-RED 250r]

but if the lights flicker on, then it wouldnt be a broken keyway..correct ? a broken keyway should result in the flywheel slipping and not creating any electrical output ?

No, not really. When the flywheel key shears the flywheel usually doesn't freely slip on the crankshaft (unless the flywheel nut is very loose). In which case you would be ruining your crankshaft. When the key shears the flywheel will shift out of position throwing ignition timing off. I suppose it could move around a little bit. The key is only there to align the flywheel in the proper position for correct ignition timing when installing the flywheel. The flywheel key has nothing to do with the lighting. The flywheel will still spin creating current powering the lights even if it is out of time due to a sheared key.

Don't pay any attention to the lights at this point. The lights working don't tell you anything either way about the flywheel key being sheared or not...It's a separate circuit from the ignition. I have seen stator failures where the lights all die but the engine runs... and vice-verca.

The flywheel key is not the main thing that holds the flywheel securely to the crank. That is accomplished by the tapered shaft/flywheel hub fit and proper flywheel nut torque. The key is only for properly positioning the flywheel when installing it... Yes, it is made to shear in the event of an engine failure of some kind, but the key is not what holds the flywheel for the most part.

No lights would point to a bad regulator or lighting side of the stator or wiring/switch problems in the lighting system.

[sunnyday]

well I just took off the spark plug boot assembly attached to the ignition coil { took it off the 250r } and put it on my 250 honda fourtrax, and there was a big fat spark...

so thats not bad...

[sunnyday]

I guess I gotta buy a flywheel puller tool.... Im thinking its a broken keyway ...wish there was a sure way to tell without pulling the flywheel off.

[sunnyday]

pulse generator and lighting coil all tested at the proper resistance/ohms...

[sunnyday]

so ignition coil, spark plug boot , pulse generator and lightining coil all seem fine.

It looks like the CD1 unit has different connector then my honda 250 fourtrax CDI unit...so I cant interchange them to check if my 250r CDI unit is bad

[RIDE-RED 250r]

Sounds like you are zeroing in on the problem. If everything else ignition related checks out, might be time to try a known working CDI. I don't have my service manual in front of me at this time, so I'm not sure how or even if you can test a CDI other than plugging it in and running it.

And yes, Honda liked to have different plug layouts on different CDI's. Most times it is because different engines have different timing curves, other times it was just an improved connector layout. I'm fairly certain the '85 and '86 CDI is interchangeable. Not sure about using a TRX CDI as I don't know if they changed plug style with the quads.

If I had a spare I would send it to you, but I don't... :(

[Mosh]

85's take a special CDI not interchangeable between any other year R.
Exactly what kind of riding were you doing when it died? If it never fired after the kicker repairs, look for something you may have disturbed during service..It happens.

Try tapping on the CDI with a plastic screwdriver handle while someone kicks the engine over and check for spark. If you get intermittent spark then suspect the CDI or connections. I have had CDI's not work in the mounting location, then if you shake them around upside down and whatnot they may work.
What condition is the flywheel? Does it look like it spent 30 years down with the Titanic? If so I would supsect the Pickup coil and Flywheel. You say you ohms tested the coils? What were the readings? Do you have an AC voltage signal coming from the exciter coil? Ohms test does not mean that the pick-up and exciter coils are capaple of transferring the proper voltage signals. In which case I would suggest a whole new stator and Flyhweel.
Many times, the connections get loose in the wire harness, specifically at the CDI and Stator plugs from years of vibration.

Also dont rule out the On switch. They can short to ground and kill the coil.