Interest in 8 plate clutch conversions?

Would you be interested in an 8 plate clutch conversion?

  • Yes! my money's on the way

    Votes: 19 61.3%
  • Are you kidding? Those are not genuine Yamaha!

    Votes: 0 0.0%
  • Clutch? no one ever has clutch problems!

    Votes: 1 3.2%
  • Maybe later on, after I get my build/restore done and on the road.

    Votes: 11 35.5%

  • Total voters
    31
Some clutch part comparisons, interchange, years of fitment.
Clutch boss 256 341 341-03.jpg


Clutch boss 256 341 341-03 (4).JPG


Clutch boss 256 341 341-03 (5).JPG

Pressure plates, early 70-73 and late 74 on
clutch parts early late (3).JPG

Pressure plates top view 70-73 and 74 on
pressure plate early late (4).jpg


pressure plate early late (2).jpg


I didn't find any major changes in the basket. The very early 70 basket had some lighter duty cush springs
clutch basket.jpg



clutch cush springs.jpg
 
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just for info.
Clutch washers stack order.jpg
clutch view.jpg

EARLY 1970 clutch info from the factory manual.
early clutch fsm.jpg

Early, 1970 exploded parts view
70 clutch parts breakdown.png

77 parts vew should be same 1974 to 1980
77 clutch per partzilla.png

Late, 1981 on; 6 plate with spring parts
81 clutch.png

Late, 81 on, spring pack detail
81 clutch spring pack.png

Clutch handle showing the grease retaining o-ring (that's never in there).
clutch handle.png

pix 5twins; alignment mark on clutch boss must show through pressure plate hole. There are 6 bolts and 29 splines, so only ONE correct way to assemble.
clutch mark.jpg
clutch hole.jpg
 
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This is all terrific information @gggGary - thanks so much for sharing!

In my experience, the XS650 clutch (like the rest of the bike) is a good piece of machinery with robust components and reliable, if slightly finicky operation. It does require a bit of messing around to get the adjustment just right but once you get it dialed-in, it seems to stay pretty well.

By way of proof, I offer the example of the much-feared, yet charming Lucille ( :yikes: ) - my 1976 XS650C. I bought Lucille from a skilled restorer who had dug her out of a pile of sh!t <literally> in a barn with the intention of a restoration. He had too many projects and agreed to sell Lucille to me for a good price back in about 2016-17. She didn't run at all, the electrics were an absolute catastrophe with some connections being made using solid copper housing wire and Marette wire nuts (YIKES!!). The engine was free but the worst part was her clutch which was locked as solid as a frozen turkey. After some horsing around with it - without success - I just decided to think about it for a while one evening.

1976 - LF side - 2.JPG


So, I went out to the Disaster Central Workshop and sat on her and listened to some rock'n-roll while gently rocking her forward and backward in time to the tunes. In my prior attempts to free the clutch, I had lashed the clutch lever to the handlebar with a bungee and so that night, I popped her into 1st or 2nd gear and rocked forward and backward in time to the music and thought about how to balance my busy work life with my desire to do a nice restoration and how nice it would be if I could get this old gal running again. This daydream went on for at least 30-60 minutes and I was enjoying the evening of music solitude with my sad, dead, old bike - but not accomplishing anything....until I realized that I had actually traveled about 8 feet across the workshop.
Hmmmm....the engine is off, I am in gear and the clutch is totally frozen...yet, I have moved a significant distance. :wtf:

Well, that could only mean that the clutch was starting to slip - and so I tightened the clutch-bungee strap some more and started rocking in earnest - and within about 10 minutes, I could duck-paddle all over the garage - engine off but in gear and the clutch lever moved freely.

Eventually, I replaced both handlebar switches and all of the ratty wiring with brand-new parts and got the engine running. I started riding Lucille all over creation - and she worked great! I have now put more than 15,000 miles on her and have never yet been inside the engine to do anything to the clutch beyond normal adjustments. As far as I know, the clutch plates in there are 47 years old and were seized together for many years (likely more than 20 years) before I bought the bike - and yet they now function perfectly.

5EEC15B5-3721-4C0A-8C1C-D8CB4B48E73B.jpeg


The one pitfall - which Gary's last post should alleviate - is that there are a lot of spacers, washers, special radial-roller axial thrust bearings and other assorted doo-dads in the assembly sequence and the thing will NOT work properly if any of them are left out or assembled in the wrong order - so, refer to Gary's post above and get it right folks.

Cheers,

Pete
 
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A collaboration with @JRP01 and we have a successful retrofit of the later clutch boss (74-80) and pressure plate(74-84) into the early (70-73) clutch hub.
8 plate clutch conversion installed, and on the road. Smooth, solid, no slip under full throttle through 6500 RPM, and "easy" neutral finding.:thumbsup:

This is rather long but should tell you everything you need to know about cush springs/replacement. broke cush springs happens, they should be checked anytime you have the clutch apart.
As of 01/2024 I have several, used, boss/pressure plate sets for doing early hub, 8 plate conversions and a good stock of clutch hubs with intact cush springs.
 
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A collaboration with @JRP01 and we have a successful retrofit of the later clutch boss (74-80) and pressure plate(74-84) into the early (70-73) clutch hub.
8 plate clutch conversion installed, and on the road. Smooth, solid, no slip under full throttle through 6500 RPM, and "easy" neutral finding.:thumbsup:

This is rather long but should tell you everything you need to know about cush springs/replacement. broke cush springs happens, they should be checked anytime you have the clutch apart.
As of 01/2024 I have several, used, boss/pressure plate sets for doing early hub, 8 plate conversions and a good stock of clutch hubs with intact cush springs.
Thats a great help Gary, thank you.
 
A collaboration with @JRP01 and we have a successful retrofit of the later clutch boss (74-80) and pressure plate(74-84) into the early (70-73) clutch hub.
8 plate clutch conversion installed, and on the road. Smooth, solid, no slip under full throttle through 6500 RPM, and "easy" neutral finding.:thumbsup:

This is rather long but should tell you everything you need to know about cush springs/replacement. broke cush springs happens, they should be checked anytime you have the clutch apart.
As of 01/2024 I have several, used, boss/pressure plate sets for doing early hub, 8 plate conversions and a good stock of clutch hubs with intact cush springs.
BTW I installed Barnett clutch springs. The new clutch works great even when torture tested at full throttle in fifth to about 85 mph.
 
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