Ignition problem/bad cdi

[Texas30cal]

I’ve just about got my 88 build together. I got this R from a buddy who’s had it for a long time but never did anything with it. He bought from previous owner who brought it into the shop for a no spark issue. When I got it the OEM stator was gone, it had a new aftermarket cdi (red CDI 10197 found out that it a Ricks) and a new Electrosport stator in box from Tucker Rocky. It’s very lazy and seems rich but it’s def not fuel system, it misses on hard acceleration and at 1/2 throttle or more spits and pops from exhaust. I’ve read about LOTS of bad cdi problems here, the stator tests 115 ohms on pulse coil and 291 ohms on source coil , which I believe should be 190 ohms. Flywheel magnets seem to all pull the same and are evenly spaced with no rattle. I’m hoping to not have to convert it over, but have read a little about the cr250 conversion and haven’t found a real good “how to” that explains what’s involved. It seems all I find are posts with questions but never a complete description. Any help would be greatly appreciated, thanks.

[The norm]

Do you have a service manual? If not download it from this forum.  The resistance for the primary coil should be .1 - .3 ohms, secondary coil with spark plug cap should be 7-11 ohms, Exciter coil 50-250 ohms,  and pulse generator coil 50-200 ohms. Any ignition part outside of those parameters is bad.
Loren

[Texas30cal]

I actually just finally found the manual a few min ago👍

[croat1]

For the CR ignition is an easy but hard to find and lately very expensive swap.  You need the CR coil, stater and flywheel.  You also need a coil mount (pumashine and ESR make those) and stator adapter (from ESR).  Oh, and a kill switch of your choice.

Joe

[Texas30cal]

Exactly which years can be used to do the swap?

[croat1]

Exactly which years can be used to do the swap?

I’ve seen 1999 to 2007 used.  I’ve personally ran a 1999 and currently running a 2001.

Joe

[Texas30cal]

👍

[Texas30cal]

Everything checks out per the manual, the source coil is a little higher than specified but according to electrosport it’s good, they also had me check peak ac output which is good at 30+ vac. I got Ricks to send a cdi since it came with one of theirs  my buddy had that was new and did not run correctly but the second one is a lot worse…..going to go ice my ankle now, never even got it to start. Who’s got a used OEM cdi for sale? The used cr ignitions I’m seeing are not even a option at this point, too much $.

[The norm]

I was talking with Eddie Sanders a couple years ago about CR ignitions. He was running a 1998 ignition on his CEO 391. I believe he said 1997 and up are a great improvement over oem trx250r. I am personally running a 1999 CR250 on my R.
Loren

[Jerry Hall]

Everything checks out per the manual, the source coil is a little higher than specified but according to electrosport it’s good, they also had me check peak ac output which is good at 30+ vac. I got Ricks to send a cdi since it came with one of theirs  my buddy had that was new and did not run correctly but the second one is a lot worse…..going to go ice my ankle now, never even got it to start. Who’s got a used OEM cdi for sale? The used cr ignitions I’m seeing are not even a option at this point, too much $.

Step one

Using a peak voltage tester:
Back probe the wire from the CDI box when it is connected to the terminal on the ignition coil .  It should be at least 100 volts.  If you are getting at least 100 volts peak at this terminal, the stator source coil and the stator pulser are working fine and the spark making portion of the CDI box is working.  The ignition coil, or the spark plug wire or spark plug cap, or the spark plug is bad if you are not getting spark.

Step two

If you are not getting at least 100 volts peak at the terminal on the ignition coil that is connected to the CDI box, disconnect the stator from the wiring harness and check the stator output.  Peak voltage on the stator source coil should be at least 100 volts and peak voltage from the pulser should be at least 1 volt.  The lighting ac coil has nothing to do with making spark.

Step three

If you are getting 100 plus volts from the source coil and over 1 volt from the pulser the CDI box is bad.

The above 3 step test works on any of the magneto/CDI type ignitions that I have ever tested that have a stator source coil, pulser, CDI box and ignition coil.   With this 3 step process you never need to check or need to know the ohm specifications on any of the ignition components on any brand of CDI/magneto ignition. 

If you are getting spark to the spark plug but it wants to kick back abnormally, the timing circuit in the CDI box is bad or you have a sheared wood-riff key.  The Honda CDI boxes on the 250Rs are bad about the timing circuit going bad.  If this timing circuit is bad it will usually have the timing advanced to around 45 to 60 deg BTDC at cranking RPM.

[2ndmoto]

That's is great info Jerry. Thank you for what you do

[Texas30cal]

Yes it is, I have my fluke and peak voltage reading adapter (from suzuki iirc) and will test tomorrow then report back, thanks!

[Texas30cal]

Well I just got back to this, are your voltage numbers ac or dc?

[Texas30cal]

After speaking to a engineer that works for electrosport who made the stator I have, the pulse coil polarity was reversed , after swapping pin locations at the connector , now blue goes to green and green to blue it runs great. He explained that due to the types (quality/cost) of components used in the cdi’s that most are polarity sensitive, that there are more expensive higher quality components (prob what the Japanese use) that make the cdi not polarity sensitive, which may explain why different cdi’s behaved differently with this pulse coil being wired backwards.

[Jerry Hall]

I bought some new CDI boxes for the 85-86 ATC 250Rs,  TRX250rs, and another ATV for around $10.00 apiece off Ebay just to see if they were any good. 

I could not start the ATC 250R because it would kick back to hard.  I put a timing light on it when kicking and the reluctor was triggering off the leading edge of the  flywheel bump.  I switched the wires on the reluctor at the connector and now it would start and appeared to run fine.  I proceeded to check the timing curve and it was the wrong shape and a mile off, so I put CDI box on the shelf. 

I checked the timing curve on the TRX 250 R box and it was different from the 85-86 boxes.  It was also a mile off from the timing curve that Honda put in the stock boxes.   I would recommend that you check the timing in your CDI box before you ride it hard to prevent hurting a piston