1986 ATC 250R Possible Stator Issues

[Rocketblt]

Hey everyone. This is my first post on here in the 4 years that I have been a member of this forum. (Sorry been splitting cases plating bolts and powder coating frames.. hehe) There are some very nice restorations on here by the way. I love view that stuff. I will show pics of mine when i get it off the ground just been playing with frame and plating last 2 years.

My R that I ride, I swapped the original motor last year with a stock motor that I bought off ebay. I have been having trouble keeping it running smoothly. It seems to bog at about 1/2 throttle, and sputters rich smoke. Runs extremely rich. (Checked plugs. Oily)

Here is how this story all starts. Last July I threw this motor in after cleaning up cylinder and rings with a hone. Compression is good. Holds good @ 160psi and still holding. Last year I attempt to fire this motor up. It backfired three times. I trace the problem to faulty eaten up magnetic pickup strip on flywheel. I replace the flywheel with my good one and and away she runs. I have maybe ridden it 6-7 times since then, and noticed it sputtering rich and hesitating at ?? 3/4 throttle, then starting doing it at 1/2 throttle. I start with the carburetor, viton needle and float good and level. All jets stock. I look at reed cage metal reeds look a little fatigue, I throw in v force 3, and she takes off again considerably. Like a raped ape! Still a little hesitation after 3/4 throttle. I go for 3 hour trail ride. Come back, shut er down, check plugs, plugs very dark. I fire her up again, Extremely loud backfire! Start her up again. Seems to run fine. Start her up week and a half later, now hesitates at half throttle again, still running rich. I go through a week of hell swapping for leaner jets, different needle positions, different reeds, different carburetor, SAME PROBLEM. Bogs at 1/2 throttle, runs extremely rich. Idles beautiful. Nice chocolate brown color on the idle circuit with a new plug. Returned all parts back to stock, jetting, reeds, everything, problem persists.

I'm going back to popping off the mag cover and checking all electrical specs if my dipstick brother ever remembers to bring me the shop manual, and it stops raining :mad But what I am starting to suspect is electrical related, and what my main questions are?

On the original flywheel. What would cause the magnetic pickup strip on the flywheel to be all gouged up? Imbalanced crankshaft? Bad Woodruff key? etc? ... I am, wondering if this is happening now with the good flywheel I have on there now. Also... Would this theoretical electrical issue mask a jetting issue? This is occurring in a specific RPM range? It almost sounds like there is a rev limiter when this occurs at 1/2 throttle..

Has anyone ever had this experience, and is it electrical, crankshaft, woodruff key,stator, flywheel related?

Any help with this issue would be greatly appreciated, and prevent me from using rogaine.. hehe.. I'll owe the lucky one a and a couple of quarts of HP2 smoke.

[MonroeMike]

There's a manual here, if you don't want to wait for your dipstick brother.

http://72.52.143.80/~trikes/atc250r_...vicemanual.pdf

[JohnR.]

Its definitely not uncommon for the stator to go bad. I've seen several of them myself.

[85Tecate]

You say its rich and your plugs are oily. Why wouldnt you assume you have a partially fouled plug? My T3 fouls plugs like no other because i havent got it jetted right. Everytime they begin to foul my engine will run like and backfire. Swap to a fresh plug and see what its like. The bog is likely too big main if its 3/4 throttle bog with an oily plug. Drop a size and recheck the plug.

[Rocketblt]

This one goes to Tecate 3 and I quote

"I go through a week of hell SWAPPING FOR LEANER MAIN AND PILOT JETS, Different needle positions, different reeds, different carburetor, (Sorry what I mean by different is a spare stock OEM items) SAME PROBLEM. Bogs at 1/2 throttle, runs extremely rich. Idles beautiful. Nice chocolate brown color on the idle circuit with a new plug. Returned all parts back to stock, jetting, reeds, everything, problem persists."

I appreciate the help though dude. It was the ignition coil. I spec'd out the electrical today all looked good except the primary coil resistance, but then again my multimeter couldn't give me an accurate reading on something that low. .01- 1 ohm
So I just blindly swapped out for another known good coil. She revs nice and high now, but still not perfectly steady at the very top end of the rpm/powerband. I also noticed the lightning coil was a little iffy too. I'm going to lean out the main 2 sizes down from stock 145 and do some plug chops tomorrow and see where I get.

Shpank you for all who helped.

[MonroeMike]

Glad you got that figured out.

[85Tecate]

This one goes to Tecate 3 and I quote

"I go through a week of hell SWAPPING FOR LEANER MAIN AND PILOT JETS, Different needle positions, different reeds, different carburetor, (Sorry what I mean by different is a spare stock OEM items) SAME PROBLEM. Bogs at 1/2 throttle, runs extremely rich. Idles beautiful. Nice chocolate brown color on the idle circuit with a new plug. Returned all parts back to stock, jetting, reeds, everything, problem persists."

I appreciate the help though dude. It was the ignition coil. I spec'd out the electrical today all looked good except the primary coil resistance, but then again my multimeter couldn't give me an accurate reading on something that low. .01- 1 ohm
So I just blindly swapped out for another known good coil. She revs nice and high now, but still not perfectly steady at the very top end of the rpm/powerband. I also noticed the lightning coil was a little iffy too. I'm going to lean out the main 2 sizes down from stock 145 and do some plug chops tomorrow and see where I get.

Shpank you for all who helped.

Glad you figured it out as well. Now that you mentiond you found the problem in the coil, im going to check mine. I, too have been having a very similar issue with mine with no luck jetting either. Fresh bottom and top end, no seal leaks. Thanks for the info.

[Rocketblt]

Tecate . Have you spec'ed out your ignition coil yet? If your coil is bad try service honda for a new one . I know its about $50 21121A COIL-IGNITION
21121-1170 (replaces 21121-1161) 1 $52.84 but that's the best deal I can find so far. From what I'm aware of. (Bear with me Im a cuban cigar and a black russian to the wind ... hehe... ) The primary windings of the coil load up the juice from the ignition coil on the stator in your case, and are usually the first culprits to go from what i've read online. The secondary is what gets outputted to the spark plug cap, and obviously from my own idiocy of playing with jetting for 2 weeks, this can mimic jetting issues.

[Rocketblt]

Ok... 6 months later and back to square one. The 'ol R is still fouling plugs on a daily basis, and still smokes excessive. Now even fresh plugs bog rich at past 1/4 throttle, and they are gap to a BR9ES .35mm which is spec.

Here are any considerable changes that I have made since the beginning of this problem. The prior engine I had in the R, I do recall having a bit of a slightly rich condition as well, but not as significant as this one. But then again the original engine was bored up to .80 over or 269cc or 265cc or whatever it is, so it probably compensated for such a little bit. I have kept ignition and jetting stock through out the duration of both engines. The spare motor I which I put in runs excessively rich, ie wet plugs from idle to mid range. When I first looked at the spare motor it would backfire and not run. The side of the flywheel was stained brown, and the magnetic strip on the flywheel was worn and chipped. I swapped out the flywheel and magnetic pickup off the original motor I removed, and put that known good part on the spare motor.
Which now leads me to a running, but yet excessively rich motor.

Last Oct the plug idled dry chocolate brown, and started to get oily wet in the mid range.This May, it idles mildly wet on a new plug on the porcelain. All plugs foul in 3-4 hrs of trail riding time. 1/4-1/2 throtle in the trails and WOT on straights. In good confession, I must say I have been running the spare motor the whole time with a minute external water jacket leak due to a cracked head dowel bolt, but compression holds cold @ 160psi for 24 hrs. (Hmmm?... I should try that with the radiator cap removed and see if I lose compression ie the leak is pressurizing radiators.) I will replace the bolt re-torque the head and submit my findings.

For any insight to who maybe be reading, here is a list of what I have checked, and what I have replaced with old and new parts.

New parts: new vi ton needle, new float(float is level), stock jets, (I'm running at 1000ft.) new jet needle R1468N Keihin DGJ equivalent on 3rd clip, air screw set to 2 1/4 turns, Vforce 3 reeds and cage, new cdi, new plugs on a daily basis, BR9ES gap to .35mm. New Kill switch. Air filter is either Uni Filter, K&N or stock. Have ran mixture at 32:1 and 20:1 with BP 93 octane gas with Valvoline multipurpose 2 cycle oil. I will dump the gas and retry HP 2 premixed at 32:1 for the hell of it if I am running an inferior oil.

Reused parts: Wiring Harness, (with a hairline crack on the ac regular wiring insulation.) Stator and magnetic pickup, (Off original motor.) Check all specs with multimeter ohms. Checks within range. Used non oem high output coil, wire and spark plug boot from original purchase of trike. (The guy who owned this trike was a real J.O. and a thief to boot. Shipped the bike with no piston and muffler cut, and welded on grab bars. He contacted me for a want from ebay. Don't ever do business with a Jeff Neece from Illinois.)

Anyways, I was researching articles on known stator issues on the R and I have a feeling that someone here is going to tell me what I am reluctant to hear but welcome it anyway. Either-its going to be a suggestion of the water jacket leak, the possibility of the crankshaft bearing and seals going which is what probably caused the initial stator and flywheel to wear out and is now possibly wearing the original one and causing less spark output, maybe its the wood ruff key?.. Or the two case bolts to the right of the stator walking loose, or even the hairline crack in one wire voltage regulator. Ill check all these for sure tomorrow but I WOULD LOVE TO KNOW IF ANYONE ONE HERE HAS EVER HAD THIS SPECIFIC PROBLEM on a almost stock R, and what they could suggest could be the culprit, or even a hint of it. I will gladly listen. I would love to narrow this down, since I have already thrown so many parts at one problem. Any help is appreciated.

[Dammit!]

Sounds like what my R and a friends R have been doing. I replaced the stator and rusted up flywheel on mine but haven't had a chance to test ride it yet. It revved up fine after the swap though which it wouldn't do before.

You said the little strip on the flywheel was gouged up. Can you post a pic? Mine was pitted from rust but if it has actual gouges in it, check to see if you have any play in your crank bearings. Just grab the flywheel and see if you can move it up and down at all. If there's any play there, it might be coming into contact with the pulse generator (think that's what it's called) and causing the gouges and the problems you're having.

[Rocketblt]

Yeah that is what I am surmising that there is play in the crankshaft, and it is causing wobble on the flywheel. I was going to take pics last night of the old flywheel, which is sitting right next to me, just didn't want to wake the wifey...lol....Here are several pics of the worn flywheel I removed 3 years ago, and swapped out with the known good flywheel off my original motor. I haven't popped the mag cover off the current/spare motor that I am running since last Oct.

Not sure, but I recall the known good flywheel being pristine when I swapped it out 2 years ago. Last Oct I checked it, I think it had a small nick in the pulse generator. Just popped the mag cover off and checked for any crankshaft play, and any more additional wear on the pulse generator. The pulse generator looks good. I will clean up rust with scotch brite pad later. Other then rust from a little mud, (Due to mag cover not being properly seated due to 3 bolts missing on mag cover from last Oct. 3 of the aluminum threads in the case were stripped for the mag cover.) The flywheel looks good. There is very very minor play on crankshaft if I attempt to move the flywheel up and down and left and right. . I am unable to verify this unless I remove the flywheel and check for play The current stator was pristine when I put it on there. Here are pics of the old stator, and the current one, as well as the hairline crack in the AC regulator wire.

Now being as polite as possible here, before anyone goes, "Well there is your problem, mud, electrical and rust do not mix, or well of course! "It has crankshaft play which equal bad bearings and worn flywheel." I just want to state that since I put the current stator and flywheel on 2 years ago, it has had this overly rich problem continuously with stock filter or after market, and with original reeds and v force 3 reeds. Even the 1st original motor ran overly rich, but not nearly as bad probably due to larger displacement .80 over or 265cc with the current stator.

I understand I have a lot of variables on the table. 1.) Minute head leak. 2.) Crack in insulation in AC reg. 3.) Poorly seated mag cover. 4.) Possibility of little play on crankshaft bearing. 5.) Possibility of crankshaft seals sucking tranny oil into lower end causing an overly rich condition. 6.) Possibility of current stator being worn before being put on this motor, previously and presently, even though ohms and all electrical spec out.

Before I rip the motor out, split the cases, replace the seals and bearings, and have nothing to ride for a while. I would love anyone’s input on semi external possibilities.

Here are the conditions of what I have checked and replaced.

New parts: new fuel vi ton needle, new float(float is level), all stock jets 145 main, 45 slow/pilot jet, (I'm running at 1000ft.) new jet needle R1468N Keihin DGJ equivalent on 3rd clip, air screw set to 2 1/4 turns, Vforce 3 reeds and cage, new cdi, new plugs on a daily basis, BR9ES gap to .35mm. New Kill switch. Air filter is either Uni Filter, K&N or stock. Original piston and rings. Compression holds cold @ 160psi for 24 hours. (Hmm?..maybe the low compression although acceptable is creating an underburn resulting in oily plugs and spooge in the stock exhaust?) Have ran mixture at 32:1 and 20:1 with BP 93 octane gas with Valvoline multipurpose 2 cycle oil. I will dump the gas and retry HP 2 premixed at 32:1 for the hell of it if I am running inferior 2 smoke oil.

Reused parts: Wiring Harness, (with a hairline crack on the ac regular wiring insulation.) Stator and magnetic pickup, (Off original motor.) Check all specs with multimeter ohms. Checks within range. Used non oem high output coil, wire and spark plug boot from original purchase of trike. All connections are clean and within resistance spec.

I guess the only thing left to do try a new coil for the hell of it, HP2 oil mixed at either 32:1 or 20:1, fix minute coolant leak with new head dowel stud. If I can get the S.O.B out! I attempted to use a stud extractor last time and it was frozen solid even after being heated, and the bolt was partially cracked at the top resulting in the coolant leak at the head. Even though rings look good and ring gaps as well, Might as well throw some new rings on and re hone since psi is fairly low @ 160psi. Grab a new/used AC regulator, and a new stator, possibly replace wire harness, and last of all, pull motor, split cases and reinstall new seals and bearings if that is the cause. Either way I need these parts for my restoration trike or this one if needed so?...and finally, if all else fails…. Hiroshima the F*&%IN THING!

So anyone have this specific rich condition problem continuously?

[Dammit!]

Yeah. That is a lot of variables.

Any kind of electrical problem that causes a weak spark can result in what seems like a rich condition because it's just not able to burn all the fuel effeciently. Same problem I had. Idled fine and ran at low rpm fine but when you get on the throttle, as soon it would be getting into the powerband it would start spitting and sputtering. The first time it happened we were able to fix it by lasing the gap on the spark plug a bit and cleaning the rust off the strip on the flywheel. The second time it did it, nothing I could do helped. With the replacement stator and flywheel it seems to be fixed but I won't know for sure until I get a full weekend of riding on it.

My 350x even went through similar symptoms recently. On that one it was a bad CDI.

Definitely check to see if that slight wobble is big enough for the strip on the flywheel to come into contact with the pulse generator. That alone would cause problems. I don't know how common it is to have some wobble there but on mine, even with original crank bearings, there is currently ZERO play there.

[Rocketblt]

Yeah that's just the thing dammit!.... (No pun intended) Its intermittent. If I go with a hotter BR8ES plug and widen the gap it will run fine until about after 4 hours of riding time, then the plug will foul. Shouldn't have to widen plug gaps and lean mixtures due to supposedly weak spark.

I am starting to fathom that it is a possible combination of an original stator and magnetic pickup with operable, but reduced efficiency, and somewhat low compression 160psi. I'm trying to find a set of sudco rings for a std 66mm bore. Have the part number from sudco catalog Sudco ART piston 624-070R Std. But cant find anyone selling them. Seller on ebay has em but just in .25 .50 and so on....So Im tyring to avoid paying for a new piston and rings when I have a perfectly fine piston and cylinder walls, last I looked.

There is very little play on my stator/crankshaft. The magnetic strip is still in great shape, and the gap between the magnetic pickup and the pulse generator is spec at .016mm which is perfect. I'll tear the top end down again when I get some $$$ and replace the head stud bolt and the rings, do another hone, and see what happens. If still the same problem, then I will replace the stator. If still a problem then the motor comes out and I change the crankshaft bearings anyway and the seals in case the engine is sucking tranny oil from the case.
I have no way of knowing as I do not own a leak down tester kit, and I cant measure the volume of tranny oil in any way unless i drain it, add a specific amount and drain it again to see if there is any loss in a short period of time.

Good luck on your test ride Damnit. Troubleshooting is half the fun half the experience and half the battle.

[Macdiesel]

what is your fuel mixture ratio and what type of oil and gas you running

[Rocketblt]

Running BP 93 octane with STP 104 octane boost additive. Running Valvoline multi purpose 2 cycle oil at 32:1 and then at 20:1 just as a test to lean out the fuel, but probably enriched the oil to fuel....Plugs are NGK BR8ES or BR9ES gap is .35. All jetting is stock. Air screw is 2 1/4 turns . Clip is in 3rd groove and is stock R1468N or Keihin replacement DGJ needle. Have tried stock filter, uni filter and k&N filter. Original reeds, same issue, replaced with V Force 3 reeds. More power but still same overly rich issue. Compression is 160lpsi last I checked in Oct. 160 psi held for 24 hours. Will check again. Is on original sudco piston, rings and bore. I just honed up the walls before installing the motor. I used a 320 grit flex hone for ten passes.

I will try the HP2 oil at 32:1 with a fresh gal of 93 octane gas and see the results in case I am using an inferior oil.

But I still believe this is stator/electrical/compression related issue. Any ideas Diesel?...