'73 Clutch Plate Replacement, Tech Section not Clear (INXS!)

[OakBehringer]

Listed in the Tech section:

http://www.xs650.com/forum/showpost.php?p=1028&postcount=7

"The different packs, 6-7-6 plates, are interchangeable as a unit. As the early, thicker plates (3.5mm) are not available anymore, Mikesxs suggest removing the rubber rings and installing an extra steel and friction plate pair in the early clutch packs.
The 7 plate pack is known to increase risk of primary gear dampening spring failure.

My personal suggestion is to change in a later model 6 plate pack - straight swap."

OK, I want to do that, but I'm not sure which friction disks and steel plates I need to order. I have a '73 TX650. What is the "later model 6 plate pack"???

Preferred: http://www.650central.com/engine.htm

or from MikesXS: http://www.mikesxs.net/products-22.html#products

THANKS!
- Adam

 

[5twins]

The '74 and later model clutches use the same plates, just one less friction plate in the 6 plate version. Your best bet is to shop eBay for an '80 or later clutch assembly. What is different in this set-up is the inner hub. It has a spring-loaded bottom steel plate retained by a wire so if you want to make this switch, you're gonna need that new style inner basket. Getting a whole used clutch will give you all the parts you need - plates, inner basket, and another outer basket. Having a spare outer basket is a good thing in case any of those damper springs on the back break.

I've never needed to replace any stock clutch plates. I've never found any worn out. What you do usually need is new springs. Get the brand name ones from 3M, not the Mike's no-name ones (they suck). The softest ones (Vesrah) are good enough for most of us.

 

[OakBehringer]

Ah, so the quote in my first post was suggesting a complete clutch swap. I didn't realize that it's called a "clutch pack." Is making the swap really that really that big of a deal? Funds are low, I'd like to stick with what I have.

If I were to go to the MikeXS route, adding a friction disk and steel plate, where do I put the plate? At either end of the stack?

Oh, stop the presses, what's this? Anyone have any experience with these?

http://cgi.ebay.com/ebaymotors/YAMA...0236535QQptZMotorcyclesQ5fPartsQ5fAccessories

Thanks,
Adam

 

[OakBehringer]

Or this...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=110523331086&viewitem=#vi-content

 

[5twins]

Buying a used clutch would be about half the cost of replacing all your plates. And you would need to replace them, you can't just add 2 new ones. You use all 3mm thick new style with one extra to make up for the old stack of 3.5mm thick ones with one less plate. If your original clutch works OK, there's no need to replace it. At most, as I mentioned, replace the springs. That will cost you less than $20.

I never heard of those plates before. They say they're XS-1 but don't say how thick they are. They also offer a set for the '74-'79 bikes for a few dollars more. No mention of what brand they are. The price is good but who knows if the plates are.

 

[OakBehringer]

Yeah, it's clear to me that I have to replace them all

The second link has 3.5mm plates @ 3.99 each. That's really cheap. $23.94 for a set? I'm going to verify the outer dimensions tonight and most likely give them a whirl.

I didn't have any slipping before I tore the motor down, springs are still in spec. The reason I'm replacing the friction discs is because one was cracked. My needle bearing was seated poorly and bent... blah blah blah, I'm guessing that caused it.

 

[OakBehringer]

I guess what I'm hung up on is this line from the Tech section:

"A redesign for the TX650A dumped the cushion rings in favour of thinner and more friction plates (+1), new washers for the boss nut, new boss part #, a 2 piece push rod and an extra 5/16” ball bearing. Result? Increased risk of primary drive dampening spring damage."

WHY is there an increased risk of primary drive dampening spring damage? What variable caused it? If I go with 7 discs and an extra steel plate, am I increasing the risk on my '73?

 

[5twins]

The 7 disc probably grabs harder when you engage it so there's more stress on those damper springs. I changed out my '78 7 disc to an '80 6 disc and like the results. The original always engaged with a little bit of a clunk when taking off in 1st.

I never read that stuff about the 7 disc damaging the springs easier but it makes sense. Glad I changed mine out, lol. If you shop around, you can usually score the complete used unit for between $20 and $30.