79 xs650 clutch hitting case

Hi just to confirm my bike is an XS1b, 1971, the friction and clutch plates are the correct number and thickness for that year/model of bike. As far as I can see the only difference is the thickness of the washer "I" on the diagram. If it is not the clutch is it the gearbox? Ta Pete
 
Hi just to confirm my bike is an XS1b, 1971, the friction and clutch plates are the correct number and thickness for that year/model of bike. As far as I can see the only difference is the thickness of the washer "I" on the diagram. If it is not the clutch is it the gearbox? Ta Pete
IMO, part 'i' would not cause an issue of the basket hitting the case nor the boss locking-up. It could be an issue with the transmission.
Have you been able to operate the bike previously?
Can you post a pic of the bare mainshaft and the centercase bearing?
Is there in/out play (measurement) in the mainshaft?
 
Hi, the reason the whole engine was stripped was the clutch shaved the crankcase and metal swarf went around the engine. When stripped there were 2 x 1mm washers and a 2mm washer behind the basket. The engine is complete so I will have to restrip it!!! I agree with you as I cannot see how "I" would cause the problem.
 
Of course, that's an extra 1mm washer behind the basket vs "factory" and perhaps it was a bandaid to prevent the basket/case issue. Is the clutch basket unmodified (not re-riveted/bolted gear)?

The clutch will have to come back off to investigate - hopefully the transmission is assembled correctly and splitting the crankcase not needed. The mainshaft should have .003-.005" of "end play" and it's bearing tight against the case flange (not inset) - will be looking forward to pics....
 
Obviously, if the mainshaft or its bearing is misassembled, it will cause problems with clutch assembly. Normal pic of mainshaft bearing:
mainshaft bearing.jpg
 
Hi just to confirm my bike is an XS1b, 1971, the friction and clutch plates are the correct number and thickness for that year/model of bike. As far as I can see the only difference is the thickness of the washer "I" on the diagram. If it is not the clutch is it the gearbox? Ta Pete
OK so it is not a 79 Now
I once had this problem after a Clutch slipping on An 80
Bought a set of friction discs from a well know parts supplier Aftermarket non Factory and it hit the inside of the cover after that.
Never touched the clutch part closest to the bearing but it still hit the cover inside.

This is well over 20 years ago so I don't remember how I solved it .
I would check the discs steel for warping and Friction being the right ones
Perhaps even buy factory parts if available.
 
I have just checked the mainshaft endplay, it is over 0.7mm = @0.027.5 inch
That's more than spec., but as the clutch assy. pulls the shaft to the right as the boss nut is tightened, I'm not sure it would cause the basket to contact the case. The location of the double row bearing, of course would affect the location of the clutch assy. That bearing has a locating circlip.

Attached is YMUS Serv Bulletin on transmission shimming:
 

Attachments

  • YAMAHA TRANS SERV BULLETIN 1971 259.pdf
    449 KB · Views: 78
Do you have a picture of the inside of the clutch housing, I cannot see the end of the bronze bushing as it is covered by what looks like another 1mm spacer. Is that a part of the housing?
 
from the 70 factory manual

1680459092140.jpeg
The clutch in the 70 I'm working on had issues so I swapped in a later clutch complete.
 
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