Electrical Issues 85 250r

[Jabcon]

Last week I went out for a half our ride around the farm and upon my return I shut it off to talk to my buddy and found that it would no longer start. We decided that I had fouled a plug and put a new one in. No spark. We traced the kill switch from the handle bars to the CDI, it's good. I was informed by the PO that it had a fairly new coil installed so we decided it must be the CDI because the spark plug wire checked out fine. Bought a new CDI and installed it but no spark still. Pulled the left side cover off and found a little bit of gasoline in the bottom of it.

Will gasoline tear up a coil?

Went ahead and replaced crank bearings while i was replacing seals and ordered a new coil. Lo and behold I had spark tonight. Installed the spark plug and kicked her over. POW! Back fire. POW POW POW! Every kick was a backfire. Even nice slow kicks to prime were back firing. I decided there was no way I put the engine back together wrong and the only things new were the CDI and coil. Coil works beautifully so it must be the CDI. Put the old one back on and she fired right up.

Any one else ever have an issue with a brand new CDI? I'm not gonna say what brand until I talk with them about it tomorrow.

[Mosh]

Your post is a little confusing..

You say that "there was some trace amounts of gas under the left cover and asked if it damaged the coil"..

That would not be the coil. That is what is referred to as the stator.

The CDI is the box under the tank with a white round plug and your COIL has the lead going to the spark plug.

So if your replced the stator under the left engine cover, yes they can be bad out of the box and cause improper timing issues, or you did not have your keyway lined up proper on the flywheel and that can cause improper timing and kickback also.

So I guess what is confusing is, which parts did you actually replace?

[Jabcon]

Sorry about that. Everyone that's helped me with it has called it something different. The coil was good.

I replaced the stator and CDI. There's only one way that the fly wheel that will fit so i knew it was right. It was the new CDI that had the bad timing.

Would the gas destroy the stator?

[Mosh]

OK that makes sense then.

Most 2 strokes will have some residual 2 stroke oil mix in small amounts in the stator cover. I doubt highly it will ruin a stator unless it was totally submerged in raw fuel. Heck most of them I see, get submerged in muddy water from cover leaks and harness sealing issues and they still run, even looking like they were at the bottom of the ocean for 2 years.

85 ATC CDI boxes are their own strange animal. I am unaware of any other models that will actually interchange correctly, and I have not ever had good luck with any aftermarket replacement CDI boxes on different models. They all seem to not last long, or cut out at high RPM's in my experience with them.

What you could do is switch your harness over to a 86 ATC 250R and then you can run a 86-89 TRX 250R 2 plug CDI which are much easier to find and even have more aftermarket choices.

I have not really run into any 85 stock CDI failures on any that I have owned. My 86 TRX has failed a CDI before though.
I have had stators fail more than CDI's with no warning. I would guess it was your stator all along. If it runs good with the new stator and stock old CDI run it and return the defect CDI. FYI, most aftermarket stators I have used only lasted a few years. No where near as long as stock.

[Jabcon]

I'll probably give it another year of riding and then give it a resto/mod next winter. While I'm at it I'll throw in a different harness since all my buddies run the 250r quads.

This trike's getting to be as expensive as the '51 lol

Thanks for your input kind sir.

[Mosh]

No prob, just make sure you get the 86 ATC harness as the quad harness will be too short and not fit right.

Care to name the brand of the defective CDI just for reference?

[RIDE-RED 250r]

I concure with Mosh on aftermarket CDI's not being worth the plastic they are housed in.

I bought my R with a Ricks Hot Shot CDI and I experienced backfiring/kickback when starting and cutting out at high RPM. Those problems got worse when I did the big bore. Switched back to an OEM CDI and both problems cleared right up.

It has been my experience and that of countless others that OEM ignition components by far work best. I do have a Ricky Stator stator and regulator and they both have served me well. It seems that mainly the CDI is what you really want to make sure and stick to OEM with.

If you want/need to upgrade your ignition, talk around the campfire is that the '01 CR250 ignition package is the only way to go. I have not myself done this mod as I need my lights to work where I ride, but enough people whos opinions I value have said this and I don't doubt it one bit.

[Jabcon]

Both the stator and ignition coil are from Rmstator. Stator works beautifully. CDI not so much. They told me to send it back to them and they would test it.

Why won't the CR250 work with lights?

[RIDE-RED 250r]

Th CR250 stator does not have a lighting side, it's ignition only. I have heard you can send a CR250 stator to Ricky Stator and they can install a lighting side. But I have never looked into it. I may do a CR250 ignition upgrade at some poiint if I can set it up to run lighting.

What did you send back to RMstator? The CDI or coil? They are 2 different components. And of the 2 the CDI is most important to be using an OEM unit...

[Jabcon]

I sent the CDI unit back. We'll just have to wait and see what they decide to do. They'll either refund my money or send me a different one.

I guess i should keep on the lookout for an oem CDI from someones parts trike? I'm glad this thread finally put me over the #10 mark so I can finally access the classifieds lol