Good info there, ND. You know...that's an interesting thought you bring up about the extra compression and larger piston possibly being an issue here. Still, there have been numerous bigger bore kits over 300cc with higher compression for quite some time without an incident like dan has experienced, but it does make you think.

 

Agreed, but as with any problem...usually only a select few experience it. That or there's a major recall. The problem doesn't seem detrimental to my bike as with Dan's. There could be another catalyst that caused his bushing's to wear prematurely.

 

NDKLX Weekend mechanic here too. So far so good with the tear down. I'm taking it slow and steady. Good info from you and your bike, thanks for posting, and I'm glad yours looks OK. You sound like you are experiencing the same thing, and know exactly what I am trying to describe. I'd say that mine has done it more than 20 times but probably not more than 40. I think it's done it for a couple years. I don't remember it with the 250 but I didn't ride it nearly as hard before the 351. The idler gear came out of mine while the flywheel was still on, but it had the extra slop from where it wore out the bushing.
You have a good point about the the starter gear train being able to run backwards. It will spin backwards but I think the initial hit must have been enough to damage mine. Honestly the hiccup may have nothing to do with the damage in mine. Maybe the damage was from simply starting the bike. The idler gear shaft did look like it had some galling on it, maybe it came from the factory like that and slowly ate its way through the bushings. I don't know why the hiccuping would blow both bushings out the same way. If you did want to look at the other side of your idler gear, the flywheel is not too bad to pull. I used some locking chain pliers and the rear axle ( pics a page or two back)
I'm cleaning up some of the parts and my work area and then plan on splitting the case later today. just stopped to eat some lunch and check on the Bears game



Left the piston in the cylinder, pulled the circlip and slid out the wrist pin.


cylinder from underside




Everything cleaned up well.

 

dan, I've mentioned many times here on the forum how cheap and lazy you are, and now with that method of leaving the piston in the cylinder...well...you've made my point...LOL!

But hey!...you've cleaned everything up very nicely...looks good.

The Bears???!!!...I thought the only real team in that division was Green Bay.

 

Alfred E , admit it, leaving the piston in the cylinder is a really smart move. Way better to be "playing" with the wrist pin vs having to deal with the rings.
Dan's not lazy, he's schmart! IMHO

 

Geez TNC, nothing to do today but Kick a guy when he's down??? Leaving the piston in is my brilliant? solution to a piston ring question I had.
I wasn't sure how to treat the piston rings. Searching online some say re-use them, others say if you have it apart put new ones in, still others say if you put new ones in you need to re hone the cylinder to get a fresh crosshatch in order to seat the new rings. I'm sure everyone on here will have varied opinions too. To sidestep ALL of that, I simply pulled the circlip and removed the wristpin, and left the piston in the cylinder. I do plan on springing for a new circlip for the wristpin.




FYI to everybody else, TNC sounds wise on here, but he doesn't always make good decisions. see the pic below.

 

Great thread! How was your ACR on tear down? Seems that a sticky ACR could apply allot of force to the starting circuit over time. Ever try to kick an old XR and have it try to throw you over the bars. That ACR really makes a difference. And that epoxy idea mentioned earlier was worth a try. Great exchange of info going on here, i love this forum.

 

My ACR moves freely, still worth another look before i put it back together though. I may have tried the epoxy idea if the case hadn't been cracked.
Agree, great forum, not just because there is a ton of info here, but the back and forth too. Like TNC up a couple lines. I smiled when I read that one, then I tried to think of something smart-*** to write back .

 

The picture is worth a 1000 words. Alfred E rides again.

Funny thing TNC rhymes with Alfred E

 

She's a runner......so far I still have some other maintenance type things I want to do to the bike before it warms up, but I couldn't wait to see if it would start. Got the engine buttoned up last weekend and it was sitting in the bike with everything hooked up. Just needed fluids in and the battery hooked up. I cranked it over without gas to try and distribute some oil before actually starting it. Put some gas in and it started right up. What a relief! Running is one thing but moving is another. I had the transmission out and had swapped out some of the trans parts with a used trans I got off eBay. I put the rear wheel and chain on and went for a ride. Everything seems to be working fine. I hope it stays that way. . I may add another thread that will be easily searchable at some point and put some more pics up on it. Thanks, for all the help.
Dan



Weighed the engine out of the bike ( no fluids and no starter motor(which is pretty heavy)) 69.4 pounds.







Almost a shame to bend the new washer over


threw the tank and seat on for a quick ride around the neighborhood.