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Discussion Starter · #1 ·

The shaft spins quite freely but every 3 or more revolutions it hits a rough patch, doesn’t seem to matter if it’s in gear or not. I can try to flood the bearings with oil as it’s been sitting for years but the reality is it should probably come apart.

It seems to me I should be able to take the bottom case off without pulling the heads a d barrels off?
 

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Without the clutch fitted you have excess end float on shaft. Pull it towards you and see if there is any difference. It could be just selector forks dragging when shaft moves in?
 

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Do you have drive chain fitted?
Either remove it or loosen it off, too tight chain can easily damage output shaft bearing which then binds on input shaft.
Hopefully it's just an end float issue though?
Good luck. let us know if that's all it was.
 

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Discussion Starter · #5 · (Edited)
The engine is on the bench so no drive chain. Unfortunately it doesn’t seem to be an end play issue, my guess it’s the gears not meshing properly. Wondering if I can flip the motor upside down and just remove the bottom case half...... on second thought the cam chain would probably not allow this
 

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Just reassemble the clutch drum and the hub back on the shaft, without the clutch plates. That will establish the right amount of end float in the shaft/locate the gears, you can spin the clutch center hub to check it for roughness.
 

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Discussion Starter · #7 ·
Just reassemble the clutch drum and the hub back on the shaft, without the clutch plates. That will establish the right amount of end float in the shaft/locate the gears, you can spin the clutch center hub to check it for roughness.
A note worthy point, this motor was disassembled 10 years ago, checked out and mainly reassembled with oil on the gears and shafts, now I am picking up where I left off. No doubt most of that oil is in the bottom of the cases now.

I have put the clutch baskets back on and it still has a rough spot every 2- 3 revolutions of the shaft.... not every time but still you spin it but enough to make me aware.

Llet’s talk about the feasibiliy of flipping the motor over a taking the bottom case off without removing the heads, barrels or splitting the timing chain so I can have a better look... seem feasible?

I had a friend who also doe s a lot of motor work say “just leave it... it will just wear in to a new pattern” I’m not thoroughly convinced as the motor is on the bench now.
 

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Flip it upside down and unbolt the bottom case, it isn't necessary to disturb the top end or the timing chain.
 

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Discussion Starter · #9 ·
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Check, so if I take either 1 of the shafts out the other spins easy with no binding... obviously a lot of noise goes away because of the gears meshing. I went over the bearings, shafts, gears and shifting forks... it all looks good.

when both shafts are in there’s slight resistance just like before, only after a few rotations and it’s not as noticeable sticky but I can still feel it.

I tried rotating the gears because I’m thinking it has to be that they are now slightly out of phase from where they spun for 16,000 miles (according to the odometer) I’m out of ideas and unless someone has any other things to try I’m just going to button it up and become a new born religious man
 

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Could be a bent selector fork?
Usually quite difficult to see anything wrong unless you have them removed from case.
Rarest occurrence I've ever seen was a bent shaft. (once ver in ? thousands of bikes)
Only a few thou out over entire length but enough to make gears bind slightly.
Look for fret marks in bearing bores
Just had a thought, check bushing inside first gear, it could have just enough wear to cause a problem?
 
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