cliff
Junior Member
Posts: 42
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Post by cliff on Oct 19, 2008 17:53:12 GMT -5
I had mixed a '81 flywheel with a '78 stator. My friends, this doesnt work. This caused me to overheat a piston and rings but only after approximately 300 miles of riding. The bike would still work up to 75-80 mph but it just wasnt right. Made tuning a carb impossible. The bike would chug and miss around 2,800 rpms and wouldnt clear until well over 3,000 rpms.
After all my chasing around the definative proof was that the timing advance, at around 2,000 rpms, would be approximately 90 degrees instead of the normal 25 or so degrees. The solution was fixed today with a '78 flywheel from Ebay that pulled the timing back to normal. At first I thought it was the CDI or the stator rewind, that had an ohm reading almost 50% higher than the spec average on the large coils. NEither of these, CDI or overwound stator, did anything to this timing problem or the running of the bike. The '78 flywheel fixed it. Now it runs clean and revs no problem. Also the low RPM chugging disappeared.
Hope this helps with someone elses problems similar to mine for the future.
Cliff
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Post by davedunsboro on Oct 20, 2008 6:52:20 GMT -5
Yay a great result & fully prooven to boot . You aren't the only person to discover the stator flywheel thing I'm certain this problem came up about a year (maybe over a year ago) so if you looked back about 10-15 pages in this section ,but it can be hard to find as the topic may not have even been about the stator anyway(I seem to remember CJ commenting on it). How good would it be if everytime you got a fault you just opened a book & it told you exactly what it is ?If you could write such a book people would bow to you I should think !Cheers Dave.
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cliff
Junior Member
Posts: 42
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Post by cliff on Oct 20, 2008 7:26:48 GMT -5
Hi Dave,
I remember reading sometime ago a "possible" problem mixing different years of stator iginition with flywheels but nothing definitive.
Then I read forum member Sjef from Germany allude to a problem and the fact the SR500 has had three different stator flywheel combos and the incompatibility between them. I think Germany has imported enough years with three different ignitions where we in the states, having '78-'82 years, perhaps have only experienced two different stator/flywheel combinations.
I have read some people with problems here that were similar to problems I was experiencing that were related to the mis matched combo. This bike should rev away and the only indication of the problem maybe to check the timing including the advance.
Hope this helps someone in the future with their tuning problems.
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Post by andy on Oct 20, 2008 11:50:44 GMT -5
Cliff,Well done,big grin factor when it all comes right especially when you've spent a lot of time dissapearing up your own rearend!My question is this;does the flywheel have a part number anywhere to tell you 78 or 81 or did you get lucky and stumble across the right one?After owning my sr for over 3 years I've just found out the frame/engine numbers dont match although the different engine is definitely a 78[eur model]!! I also think the yam cdi that was on it before I replaced it with a hyperpak is from a later model.No doubt these 30 year old bikes have all sorts of replaced parts at sometime or other but not necessarily the right part!!! All good fun though.
Regards,Andy
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Post by sjef on Oct 20, 2008 16:03:39 GMT -5
Hallo ,
there are 3 kinds of stator, with the 330 ohm coil on 1,6 or 9 o`clock.all need a different flywheel with the pickup magnet on a different spot,
have here a 79 flywheel 032000-045.
best regards sjef
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cliff
Junior Member
Posts: 42
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Post by cliff on Oct 20, 2008 20:59:33 GMT -5
Sjef,
The '81 flywheel shows part #032000-077. The '81 stator shows an ink stamped # of 1411, but not sure if it is a part number.
MY '78 flywheel shows the same as Sjef 032000-045
It was your post to convince me of needing a different flywheel and that I had mixed the '81 and '78 flywheel and stator. The old '78 flywheel got lost and my rebuilt stator was from the '78. I still have the '81 stator but it too needs re-winding.
Dave I found a '78 flywheel on Ebay. I was just hoping it was going to work properly. I guess I really should sit the flywheels side by side with the stators and take pictures. I have had them apart so many times it would be a two minute job. ha,ha.
So there are three different stator flywheel combos? Dare I say that in the US we, perhaps, have only seen two of them?
The TM-36 carb works correctly now and the bike revs out wonderfully. The TM-36 puts the capital "H" in these hooligan bikes.
Thanks Sjef.
Cliff
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Post by StewRoss on Oct 21, 2008 1:42:24 GMT -5
Hi Sjef, What does an '83 engine run? I am in need of a CDI to suit, or perhaps junk the whole thing and fit something aftermarket...this bike is destined for the salt only...no lights etc. SR  |
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Post by colinjay on Oct 21, 2008 6:52:05 GMT -5
I must have been lucky, as I have mixed and matched stators and flywheels a lot over the years and never had any problems. I doubt that any of my bike are running with their original flywheel and stator sets, but fortunatly most of my SRs are 1978 models. Having said that, the XT500 that I have ridden all this season in the Reliability Trial series is running a stator from what I think was a 78 SR500 and the flywheel off of my SR400, which I think is a 1983 model. The XT has run like a dream all season and never played up in any way on the ignition front.
Stew,
My salt racer is running with the points ignition setup from a TT500. Much simpler with the wiring, however the guy who ran it up on the dyno in January said I could probably get another HP or two with a good electronic ignition setup. I am playing around with a kit ignition setup and might get around to fitting one day. I don't know if I will be able to get to the Lake in 2009, as the event is being run in March, which is the middle of "vintage" and I will have to do some serious grovelling to get some time off work.
CJ
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Post by sjef on Oct 21, 2008 10:01:09 GMT -5
Hallo Stew,
a cdi cdi 07000-035 should work when your engine is still original,
regards sjef
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Post by stacer395 on Oct 21, 2008 18:54:28 GMT -5
Hello,
The flywheel from a 1981 model should be stamped with 4R8-50 on it just past the part number, this model must kept with the same stator which is not he same as the 78 model it has slots for timing.The 1981 model has no such slots, also other slight changes in the coils, the 81 model also must be kept with the same cdi which starts with 3HI-50, a cdi with 2J2 should not be used with a 81 model. I believe the 2J2 cdi is ok to be used for all other models with slots in the stator. 4R8-50 is stamped on the flywheel for this purpose, as to not mix the models.
Steve.
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cliff
Junior Member
Posts: 42
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Post by cliff on Oct 21, 2008 21:37:06 GMT -5
Steve,
Interesting. MY '81 flywheel has no such number after the model #. It has though number and letters following model # of 2 10 S. Slots for timing? I assume you are referring to the slots in the stator that the three mounting screws go into that allow about 1/4" of timing movement. Both my '78 and '81 stator has that, not just the '78.
CDI model # of 3HI-50 and 2J2? My '81 # is 070000-035.
Steve please dont be offended but I have to ask. Are you sure your on the right forum?
Here is another interesting discovery about the '81 flywheel and stator. Both have small inked letter/numbers JS1411.
Cliff
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Post by StewRoss on Oct 22, 2008 2:00:44 GMT -5
Thanks Sjef, might have to see if I can get one from OS somewhere...I was considering getting another system altogether as this bike won't run lights or anything...that MZ one seemed an interesting device. Col, I won't be there next year either, as I have to build the bike up yet...too close for me to consider it next March myself. My brother who is going to ride the bike as well, has already had hats and T shirts made up saying 2010...so that's it then...heh, heh...I also keep changing my mind on the engine spec as well... SR |
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Post by aero on Nov 23, 2008 12:07:38 GMT -5
I'm trying to put together a list of what goes with what so if this problem arises the anwer is close to hand.
I'm thinking the set up in 78 was only used for one year?
the 79 to 83 (4) used the same set up, different to the 78.
what was the later verient in germany? was that the 1995 version?
I doubt the position of the 330 ohm coil would cause the timing to change....this just powers the CDi box. It'll be the pickup magnet -relative to the keyway position- and the type of pick up coil that causes the different timing.
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