OK guys, I'm scratching my head on this one

[big specht]

Did you alread swap out the plug? I just got done messing with a xr600 with a ignition problem that end up being the brand new spark plug I bought , swapped it out with another ngk plug and it ran like a champ. I did the same thing that everybody said to do ,get it to ack up and start swapping out parts that's how I found my problem. And never rule out a new part cause I've been burnt on that while working on cars.

[Dirtcrasher]

The one weird problem that has had me stumped a couple times was the fuel delivery.

I'd kill the motor and shut off the fuel as soon as it bogged. I loosened the carburetors drain cap and almost no fuel was in there. Both times I found semi-plugged filters in the petcock.

I tore them out and put clear inline filters and that took care of the issue. However, that was metal tanks and not plastic like yours.

Just a thought....

[RIDE-RED 250r]

Steve it's funny you suggest that as that is my exact plan if swapping out ignition and electrical components doesn't pan out.

Big Specht: swapped plugs at least three times the day this issue first cropped up it.

[deathman53]

I would say it is the coil, but if you swapped it with a known good one, it would likely be something else. I would still buy a new coil, it highly unlikely a new coil will fail on you(and they do at the worst times). Cdis are rare to go bad, it does happen. This happened to me........07 ktm 250xc. It starting not running good, stalling, sputtering, barely going and finally crapped out on me. I was at a road and just got out of the sand pit, so I was lucky. I had barely any spark, so new plug, somewhat more spark. And would start and die quickly and minutes later not start at all. I called my friend to get me. Brought bike home, got a new coil....it started, but died out quickly, it had no spark. Different cdi.....no change, new wiring harness.......no change, new stator....good spark at first and ran, but no change after it ran some. I then put in a new flywheel key.......same deal as the stator. I was getting annoyed and stumped. My builder said it could be the flywheel, its very very rare. He told me to remove the flywheel, re-install it and give it a few taps with a dead blow to seat it fully. It started after that, ran for a few and died out. I tapped the flywheel and it ran, then died out. So I ordered a new flywheel and installed it......end of any problems. The least likely thing was the problems and I wasted over $300 on things I didn't need. Swap the flywheel, your problem is likely there.

[fabiodriven]

Flywheel key! Lmfao!!

But seriously, since I was a kid I've yet to ever see a coil fail outside of the modular Ford engines and the Lincoln LS engines. It's super easy to change most times, many times not expensive, but personal experience has taught me to disregard the coil as being the problem unless further diagnosis tells me otherwise, which simply never happens. I'm not saying it's impossible for a coil to fail, obviously it happens, but my money would be on the CDI or stator as I've seen both of those fail multiple times on various machines, far more often than coils. A CDI can absolutely work periodically or whenever it decides to and then cut right out again, happens all the time. Ask anyone who owns an XR600 or XR650L about that.

I also agree with checking the petcock screen. Seen that cause issues far more often than coils as well.


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[oscarmayer]

I would say it is the coil, but if you swapped it with a known good one, it would likely be something else. I would still buy a new coil, it highly unlikely a new coil will fail on you(and they do at the worst times). Cdis are rare to go bad, it does happen. This happened to me........07 ktm 250xc. It starting not running good, stalling, sputtering, barely going and finally crapped out on me. I was at a road and just got out of the sand pit, so I was lucky. I had barely any spark, so new plug, somewhat more spark. And would start and die quickly and minutes later not start at all. I called my friend to get me. Brought bike home, got a new coil....it started, but died out quickly, it had no spark. Different cdi.....no change, new wiring harness.......no change, new stator....good spark at first and ran, but no change after it ran some. I then put in a new flywheel key.......same deal as the stator. I was getting annoyed and stumped. My builder said it could be the flywheel, its very very rare. He told me to remove the flywheel, re-install it and give it a few taps with a dead blow to seat it fully. It started after that, ran for a few and died out. I tapped the flywheel and it ran, then died out. So I ordered a new flywheel and installed it......end of any problems. The least likely thing was the problems and I wasted over $300 on things I didn't need. Swap the flywheel, your problem is likely there.

to add to this, one of the "quirks" that the Yami YZ85 engine has was a flywheel seating. the fix was the following.
take off the oil seal really good to the edge of the crank.
get some fine valve lapping compound. out it on the crank and w/o a key, slide the flywheel on. now pushing and spinning at the same time, twist the flywheel on the crank. this like valves laps the 2 surfaces to be matching when done. it takes about 5-10 minutes to get it perfectly aligned. you will know because every edge of the flywheel inside and the crank will be a light grey color. now, take some rags or paper towels, and wipe the paste off, then use carb cleaner to finish cleaning everything up. once everything is FULLY cleaned, re-assembly and use a small squirt of WD-40 on the crank before you slide the flywheel on. this will ensure proper seating and contact. this will make certain the 2 are set to be perfectly mated together and will never vibrate or wobble that could cause issues.

good luck.


side note:
are you sure your flywheel is the correct one for your year? I was informed the 85 and 86 flywheels are slightly different.

[RIDE-RED 250r]

As far as I am aware, the flywheel is an '85. Whole rest of the engine is '85. After reading the above, I am not saying the flywheel is not the cause, but I can say I don't think it's the wrong flywheel as this engine ran perfect without fail for a good while on that flywheel before this issue.

Here is something interesting I found out about the stators though:

When I pulled a spare working stator and pulse generator set out of my parts bin, the first thing I noticed was that I had to cut back and re-solder the stator output wires to their leads on the stator. The stator has several different solder contacts to connect wires to. I noted what contacts the wires were connected to on the outgoing stator were different than the way they were connected on the replacement unit. Huh???? Well, I decided just to re-solder the wires on the replacement stator to the same contacts they were originally hooked to. OK, easy enough right?? Well, I went to bolt the replacement stator into the engine and noticed that the 3 stator mount bolts I just pulled out when I removed the old stator were too big to fit into the mounting holes on the replacement! Apparently, there are large and small mounting bolt stators for the 250r. I have no idea what sizes coincide with which years, but they are clearly different in that respect. I had to drill out the mounting bolt holes on the replacement to mount it up. Maybe this is a well known fact, but I certainly was caught unaware!

Anyway, the good new is that my soldering job was good, and the trike fired up complete with fully functional lighting.

I just got home from my son's little league game, so I didn't get a chance to take it out for a test run today. I will be doing so by no later than this weekend.

Thanks guys for all of the input. It's good to have fresh opinions and suggestions at times like this. If the problem persists, I'll shut the fuel petcock off immediately upon the symptom's return and check on how much fuel is in the bowl. If fuel doesn't seem to be a problem, I'll swap in a spare CDI. I had the good fortune of scooping up a couple of known working '85 style CDI's from another forum to keep on hand a couple of years ago.

[deathman53]

maybe you have a stator from another bike in your parts bin???? most places list 85-88 stators and flywheel the same(even though flywheels were slightly different weights over the years), they list 89 stator as different-it has a different connector, but otherwise the same. 89 flywheel is the same as 85-88 flywheel also. I have 85, 86, 88 and 89 stator, they are all identical in the mounting. If you don't use lighting, go with a cr 250 ignition, its much better, esr has adapters for the 00-01 and 02-07. You can get lights for them too, there is lighted stators sold for them also.

[RIDE-RED 250r]

Hmm, what you are saying about the stators is interesting.

The stator I had to drill out the mounting holes is visually 100% identical to the one I removed, with the exception of the mounting hole size and wire connection locations as I mentioned. I don't remember if it came out of my '85 parts engine I have sitting on the shelf, or if it came out of my big bore R that I replaced with a Ricky Stator unit a few years ago. Funny story there, I replaced that stator trying to remedy an issue that ended up being caused by the Hot Shot CDI that trike was running when I got it...

The "small hole" stator looked like it used the same size bolts as used to mount the stator cover, clutch cover, etc. What are they, 5mm??? They are the ones that have the 8mm head. The "large hole" stator I pulled out of the engine had larger Phillips screws. I guess it's entirely possible that someone, somewhere along the lines stripped the threads in the stator mount holes, then drilled and tapped to the next size up??

[82 250r]

The stock bolts should have the 8mm head. You can see one of the bolts in this pic

[oscarmayer]

glad it worked out sir! keep us informed how she runs this weekend!

[JesseA420]

i vote put a cr ign in it

[RIDE-RED 250r]

Well, I spoke with my brother today who is the previous owner of this particular engine and asked if he ever needed to drill and tap the mount bolt holes to the next size up and he said he did not. But he did say he thought the hardware (3 large zinc plated machine screws) was a bit odd when he had to replace the stator and flywheel when he owned it due to a flywheel failure.

I'm thinking someone did the drill and re-tap at some point over the years.

Anyway, I got it out and rode it for about 20 minutes and so far no trouble. Usually the problem would manifest in less than 20 minutes of ride time. It's looking like the stator and pulse generator swap might have cured it, but I won't be sure till I get more ride time on it.

Will post an update when get a chance to take it out again.

Ya know what guys, a little food for thought that just struck me out of nowhere: At one time I owned a '98 Arctic Cat ZR600 EFI. These sleds were notorious for stator failures. And As I sit here hashing this over in my mind, I remember when the stator went out on that sled. It acted exactly the same way this R is/was acting. It would idle, somewhat, but would not take throttle for beans. Shut it down and let it sit a few minutes and you could ride a few minutes again and the cycle would repeat.

Jesse: I'd love to do a CR swap on both of my R's at some point.... All in due time.

[Dirtcrasher]

All flywheel key shearing aside, lol; The ONLY issue that left me stumped (even left it home for TF) was out of all my 86 350X crate motors, one had a larger ID flywheel. It fit, it bolted up, it had spark. But NOT enough to start it.

I had figured every 86 stator/flywheel would be the same, but nope.....

I had screwed it all up by using a different flywheel because I had lightened the original on my lathe. Never ever have I seen that happen before and John was a witness

[oscarmayer]

Well, I spoke with my brother today who is the previous owner of this particular engine and asked if he ever needed to drill and tap the mount bolt holes to the next size up and he said he did not. But he did say he thought the hardware (3 large zinc plated machine screws) was a bit odd when he had to replace the stator and flywheel when he owned it due to a flywheel failure.

I'm thinking someone did the drill and re-tap at some point over the years.

Anyway, I got it out and rode it for about 20 minutes and so far no trouble. Usually the problem would manifest in less than 20 minutes of ride time. It's looking like the stator and pulse generator swap might have cured it, but I won't be sure till I get more ride time on it.

Will post an update when get a chance to take it out again.

Ya know what guys, a little food for thought that just struck me out of nowhere: At one time I owned a '98 Arctic Cat ZR600 EFI. These sleds were notorious for stator failures. And As I sit here hashing this over in my mind, I remember when the stator went out on that sled. It acted exactly the same way this R is/was acting. It would idle, somewhat, but would not take throttle for beans. Shut it down and let it sit a few minutes and you could ride a few minutes again and the cycle would repeat.

Jesse: I'd love to do a CR swap on both of my R's at some point.... All in due time.

Awesome news! Glad it is working for you! Enjoy it!!!