Extra Parts in transmission?

Well, I've got some good and bad news. The good news is, I pulled some extra parts our of my transmission today. The bad news is. They're not extra parts. As I was going for a ride when shifting down to first at an intersection I heard some grinding noise, then, when coming away from the intersection, I can't shift. Stuck in first. So I ride back to campus in first and let the bike cool down and pull the cover with tithe shifter lever off. Nothing abnormal, as I look in the little hole with the shift drum though, I see a jaggy thing, so i take my flash light and poke around a bit. and I pulled this out.

Mystery Part

Can anyone identify this mystery part? It's strange cause after I got it out I was able to shift through all the gears fins and without a problem with the occasional jam (I assume from more chunks of whatever that is. Does this mean I'll have to split the case and pull it apart? I fear the worst. Thanks for any input.

-Jared

 

That will be a broken chain guide.
These should be helpful

http://xjbikes.com/Forums/viewtopic/t=4181.html

http://www.xjbikes.com/Forums/viewtopic/t=15298.html

But I havn't had this problem yet.

 

oops...error

 

Just finished this exact job myself Chunga. What a pain in the backside but a great learning experience. I now fully understand clutches, starter drives, etc. The things that got in my way were mostly me doing something dumb like missing a bearing retainer and having to re-split the cases. So take your time, keep the parts organized and take your time. Too bad such a cheap part causes this much work but what can we expect after nearly 30 years inside an engine?

Of course I never had all the tools either, so buying bits sapped time and resources too. For example the clutch pack nut is 30mm, some engine bolts are 17mm, etc.

You must get this fixed and soon. In my crankcase were thousands of pieces (22 large ones) that choked off the oil pickup screen so badly that I do not know how we managed to limp home without spinning a bearing. This was in addition to the shift-jamming pieces that were crammed in every nook and cranny of the dogs, cogs and channels of transmission parts.

While most people advise a total tear-down to get at cam chain and primary chain replacement, my job did not go that far. This risk was taken as the engine had great compression and ran like a top. Plus my limited skill and patience would not havbe been able to deal with all the parts and associated assembly complexity.

If you get in there without tearing the top end apart, you will have to rotate the crank to worm the remains of the chain guide out and the new one in because the counterweights of the crank will likely be in the way. That's OK to do as the cams, pistons and crank are all still attached to each other, so there will be no timing issues.

Just be sure to get ALL of the pieces of the guide out of there, take out all the gears and forks - don't be afraid - and get a Haynes manual as the description is about 5,000 times better than the Yamaha Service Manual. As one of the threads linked above says - it's better to do it once. Not the several times I had to.

Oh yeah, one last thing - make sure the air box is in the frame before you put the engine back in...not like my last mistake...

 

Well that's better news than I expected. I thought I was going to need a new tranny or something. And it's even better that it's a cheap part! As a college student I have more time than money, so it makes it a lot easier for me to do something time consuming rather than money consuming. I will just have to get to a garage out here and get it done. Thanks guys!

 

Well, time has come and gone and my bike is still sitting in the school parking lot, bathed in WD-40 to prevent rust and still out of commission. I took the oil pan off and I was able to get all the chunks out of the engine and I cleaned out the oil sump as well, not as many chunks as I have heard about from some of the others with this problem. I have read about the ideas from chacal and others that it might be possible to replace this part without having to pull and split the engine. If people would like, I would be fully willing to give this a try and make a tutorial out of it for others. I have a service manual and I would do anything to get my bike back on the road, I just need the technical assistance to give me a nudge in the right direction and keep myself on track. Would anyone like me to try this? If I can get it done it would certainty benefit others on the site. I have about 4 weeks of classes left then I ship off home, which is where I will start pulling things apart and making a guide out of it if you guys want. Let me know and I'll be sure to queue it up as one of the first things I do once I get home.

-Jared

 

Well Chunga, you could certainly try this and post the results.

Problem is that the transmission gears, shift forks & drum all block access to the guide and must be removed. Besides, the guide replacement is only half the problem. The main half of the problem is the plastic shrapnel that sits in the shift drum channels, between the gears and dogs, preventing engagement of gears. The entire transmission needs to be disassembled to prevent doing the whole thing over again when you get it back in the bike and realize you still don't have all the gears you should.

All it takes is one missed piece and the work has to be done all over again. Please take the time to split the case. Even if you find nothing else, it's the only way you'll know for sure. Splitting now is far better than doing the whole thing twice.

Been there, done that, don't ever want to do it again!