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Discussion Starter #1
So I just picked up a 92 Timberwolf 250 2wd as a fixer upper, but now that I have undone all the previously screwed up repairs I am stuck on an ignition issue.

There is tons of spark, and the stator and pickup checkout OK. It looks like there is a new ign coil on it. I pulled the flywheel and checked the key, and its fine. Initially I could only use the electric start and suspected a weak starter, but I tuned it up and its working better. Once I got the rewind back together I confirmed that I have a timing issue. Give it a pull and there is severe kickback. It wont start with elec. or rewind.

I suspect the CDI box, but am looking for suggestions that might bail me out of a $200 bill.

Thanks gang
 

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I have no experience with a 250, but did you check the valves as part of the tune-up?
 

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Discussion Starter #3
No I haven't done anything with the valves yet. Its on the list though. Does anyone know if there is a decompression mechanism on the 250? Other motors have a centrifugal release that comes on at low RPM.

So I did get it going..... I disconnected the battery and used the pull start and no kick. It started easy, but if I reconnect the battery, ouch! Battery is good though. Lots of voltage and turns the starter nicely, but it wont start.

?????????????

BTW thanks for the reply ridgway
 

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I didn't see a decompression mechanism on partshark. How's the chain tension adjustment set? Bottomed out? like there's a lot of slack in the chain.
How's the cam gear look? worn?
 
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Discussion Starter #5
Well the valves were set OK, and the chain and cam timing are right on. Once I got it running I took it for a little rip and it works pretty good through the gears, but once you get it back and idling you can hear the excess advance, and it runs rough. The kick back is still present and its tricky to get going. Once the battery is hooked back up there is no starting it.

Eliminated the stop switch, checked connections, grounds, but no difference.

Im thinking CD box. I might have another one kicking around that I can gerrymander in there, and see if there is any change.
 

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.......Once the battery is hooked back up there is no starting it...................
Meaning you can't start it with the pull rope and you can't start it with the starter??
 

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Discussion Starter #7
Meaning you can't start it with the pull rope and you can't start it with the starter??
That is correct, once the battery is hooked up the ignition fires too early and pulls the rope out of my and or at least stops it dead.

The machine is an early '92 and the stator doesn't look the same as the parts breakdowns. It has a separate charge and source coil and isn't a one piece stator.

I have a feeling that its the CDI though. It must be firing at a lower voltage than stock causing the early timing. I am going to find another CD box today.
 

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Discussion Starter #8
So an update on the testing.... I couldnt get the other CDI to work. Its off of an old Kawi and unknown cond. The coil is new looking, but I discovered that it no longer has a resistor type plug cap on it. It does have a resistor plug in it though, but I'm going to try a new cap on it anyway. I suspect that with the new coil the prev owner may have run the stock non resistor plug, but I am unsure if it could effect the CDI. I read that it can damage the box. Retested the source coil and its a bit out, but the trigger is fine which dictates the initial timing. Gonna try a new cap. Still hoping to save myself from spending on a new CDI.
 

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Discussion Starter #10
So I ordered a new CDI from regulatorregulator.com. I was beginning to wonder if the site was legit, but they did ship it and I am now waiting for it to get here. Another week I suspect.
 

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Discussion Starter #11
K so I got the CDI installed and there is a big difference in starting now. No more kick back!

The trouble now is that it wont rev out. When I was able to get it started with the old CDI it seemed to run pretty well at higher RPMs, but now it lacks power off idle and it backfires badly through the carb under load. I thought it might be too lean, but after adjusting the carb, thats not the case.

Think I got a bad CDI?
 

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I say backfiring through the carb is the result of valves not closing completely from poor adjustment, or the plug is firing before the intake valves are closed which is a timing thing.
Maybe you have a bent or burnt valve not sealing. Have you done a compression test recently?
 

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Discussion Starter #13
Thanks for the reply ridgeway, but I have checked all that stuff already. Looks like I got a bad CDI out of the box :-(

I plugged my old one back in and it works better than the new one. The new one works better at idle, but Im not getting any timing so the power is totally lacking. The old one doesnt idle for shit, but when I get on the throttle there is all kinds of power and there is no backfire. I can get it going if I roll over TDC and then give it a good pull. Burns oil pretty good too, but not catastrophically bad. The trigger coil tested out fine, but maybe its worth another look....
 

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A Chinese CDI could have been built for a multitude of machines but not yours
Just because it will plug in the seller probably thinks it will work on your make and model. OEM

My 2.0162¢
 
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Discussion Starter #15
K so a little more progress on my rig.... well actually a giant leap back :-( As you all know the new CDI didnt make a huge difference in the machine and I have been struggling with the stator. The struggle is that it doesnt look like all the ones that I see for sale or in the parts breakdowns. I was checking around and stumbled over a rewind assy for an '85 tri moto 225 that said it fit a 250 timberwolf too. Wondered about the stator... was it similar? Well FML there is was. A lot of the components look pretty much the same too.

WTF am I dealing with here? Someone else's joke of a repair or an early '92 that used a 10 year old ign system?
 

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It's hard to say what has been done to some of those older machines. Your best bet might be to bite the bullet and buy the good stuff, as you know it will work, or wait around for some used stuff to come up but then your back to gambling
 
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Discussion Starter #17
It's hard to say what has been done to some of those older machines. Your best bet might be to bite the bullet and buy the good stuff, as you know it will work, or wait around for some used stuff to come up but then your back to gambling
The trouble is that if I upgrade the stator then I have to replace the flywheel.....

I found the specs for the trimoto and the source coil as well as the pickup are in perfect condition. If I get a hold of the tri moto cdi I might be OK... OR some guy through that old stator in for a lark, and what I really need is just a new stator, with the flywheel and cdi being OK.

I hate dealing with unknowns. Going to check in with the dealer I think. See if there was a serial # break.
 

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Discussion Starter #18
K so it looks like a factory stator setup, and yes its the same as the 80's 225 tri motos..... Went to the dealer today and he showed me yamaha-motor.ca and .com for parts lookup. The two sites show different stators, but have the same CDI part number. I guess there must be some of both out there or maybe we got a different lot up here in Canada.

Anyway the source coil tests out at 385 ohms and the spec is 330 +-20% which means that its high but not out of spec. The pulse coil is bang on at 196 ohms (200 is spec). I am going to check the wiring again to make sure everything is indeed legit.

Anyone have any more advice? Do I really have two bad CDI's or WTF....

anyway thanks in advance
 

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Discussion Starter #19
Holy smokes boys! I got er going! I got a used stator from ebay off of a 200 trimoto that was in better shape than mine. Although coils measured out almost the same with an ohm meter, mine had been cut and soldered together in several places by the previous owner. Once I figured out the difference between the US and Canadian model and that a 200 or 225 trimoto stator would work I just had to find one for the right price. I also reset the timing chain tensioner because the chain seemed a bit tight. Once I got her all buttoned up she purrs like a kitten. Of course the starter clutch is acting up now, but she runs! FINALLY. What a tricky little sucker....
 
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