Countershaft freeplay

[Bigfoot]

what about the shift forks themselves. I guess in this case it would be #3. I have seen them where the contact surfaces (whatever they are called) have been completely ground off. If that was the case, it would cause 1st to not engage fully, producing the results that you are describing. Or a bent shift fork (but you said they look straight. Your symptoms are exactly what was happening with both my bikes when I got them. Back cutting the gears solved the problem.

[petejw]

Thanks, I was hoping you guys would chime in.
heres a pic of the washer and bolt and 1st gear dogs.



and as TC stated,
the bearing in the case is thinner and the washer is used
to take up the slack.

Ill take the sump off and have a look and try and take some pics,
TC the shaft pawl was originally off alignment and i was having difficulty changing in all gears and couldnt get neutral, 1st gear was also slipping, when i adjusted that, fixed all the gears but first still slips.

[trbig]

The washer you have there on the shaft next to the spring clip looks to be the one that goes on the outside of the case along with another washer and the bolt. #32 in this pic.. It looks much thicker than the stock washer that goes there and would hold 1st too far away.. and would get the machine gun sound.. and would also mis-align counter shaft, along with the rest of the gears.





That being said.. I don't see what appears to be the correct washer (#17 ) that goes there in your pic..


Tod

[petejw]

The washer Ive got on the shaft is no 17 on the diagram,
the problem ive got is that ive pulled 2 engines down at the same time
in a small area,as much as ive tried in keeping the parts seperated i might have mixed some up.
Looking at both the washers in front of me from the other engine the washer on the shaft is bigger and thinner than the washer sitting on the book.
the washer on the shaft is 2mm thick does that sound to thick? do you know what the correct size washer is?
I was just having a closer look at the diagram and comparing it to this one on the uk site

http://www.benefiscal.co.uk/stage%20...e=TRANSMISSION

number 29 is different it calls it a collar where this other one is a washer.
now im confused.

I just went out and put the gears backin the spare engine, the washer thats on the shaft if i put it to the outside of the casing with the other bolt and washer it covers the bearing completely and wouldnt allow oil to pass.

Are the 81 models over here the same as the 81 models over there?
Im just wondering what part number 29 is?

[trbig]

I am still down at John and Kat's in Texas, but will be home later this evening. I have a set of gears handy and can get you some measurements and pics of the washers when I get there.

Tod

[petejw]

Thanx,
but you get well and take your time.

[trbig]

I'm fairly certain that I am getting more sympathy from you than I will get from my motorcycle hating wife.. lol.

Not a problem.

Tod

[TopCatGr58]

Hey Pete,

The washer for the thinner bearing in the 81 is ALREADY in the engine, it's mounted between the bearing and the engine case on the outboard side, that's part #29 you're seeing in the exploded view, they just don't show the position of the engine case, same thing for that "C" ring/circlip #27 that holds the bearing inside the case. The outer bolt and large washer, and the smaller COLLAR washer is all that is on the outside of the bearing and engine case. The large washer ON the bolt has a shoulder, and you have to make sure that the collar washer it properly positioned to match up with that ridge on the washer/bolt while it's fitted to the shaft and engine.

Part #17 is the washer that's on the gear shaft that fits between the 4th gear wheel and the 1st gear wheel. The photo is a little out of focus for the 4th gear dog that is directly in line with the gear shaft, but it's profile looks like it's slightly rounded off, it doesn't take much. You haven't shown the 1st gear wheel, but I would suspect that the 6 shoulder/flat slots are also slightly rounded off, and that's why it's slipping. You need to take a die grinder and diamond bit/or Dremmel to both to put a slight undercut on both surfaces. That should solve your 1st gear slippage/skipping.

That's my perspective on what I see!
T.C.

[petejw]

Thanks TC that makes sense, in the pics those gears are
off the engine thats in the bike now and had a known 1st gear issue when i bought it, (engine from my parts bike)
the gears ive put back in are from the recently seized engine and i had no problems at all with it, the gears still looked new, so when i put them into this engine i thought it would fix the problem, when it didnt i thought it might be something else that was causing the gears not to mesh.

Tod,
Maybe but i dont have to live with you.

[petejw]

allfixed

Yesterday arvo I took it all apart again,
heres a pic of first gear engaged, not the best pic was taken
from under the bike



heres a pic of the shift fork

there was only slight wear on this when i put it in.

I back cut 1st and 4th gears and 2nd and 5th gear,
i was unable to do the 2nd gear washer swap, i wasnt able to get the
shaft back in.
Anyone else have any problems with this on the later engines?

The good news is that all works well, i gave the bike a good run hammering it in 1st and 2nd and it didnt skip a beat, I was worried that this might not fix the problem as i used good gears from the other bike, goes to show it doesnt matter how bad the slippage is, this mod fixes it.

So a BIG thanks to those that offered advice, and to those (Ken/TC come to mind)that made this mod available to us.

[TopCatGr58]

Hey Pete,

Glad to hear you got it fixed. I'm replying here instead of my thread, but thanks for the comments. YEAH, BIG THANKS TO KEN TALBOT, it was his original tip and info that I used to do mine, I just made a different pictorial tip, but it's really KEN's tip!!!

I've never done the washer swap on any of the bikes I've fixed. The way I saw/see it, it's the angle(or lack of in the OEM) of the dogs/slots on the gears and their resultant wear/rounding off that contributes to the eventual skipping syndrome. There's plenty of contact engagement surface area when they are new, and so with the undercutting, this helps to reinforce the pulling together action of the gears under stress, and so the washer swap isn't needed, IMHO! Also, don't like the idea of a "C" clip without a washer on it, I figured the Yamaha Engineers put it there for a reason! And it's hard to find an extra washer, and then folks have talked about needing to machine the edge/side of the gear, etc.....too much work!

Hammer down Pete! T.C.