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Discussion Starter #1
Hi fellow inmates.
Has anyone else fitted a Yoyodyne slipper clutch to their RC8 ??
Have any of you had/seen this problem…..

Did an oil change and there was a significant amount of aluminium particles glistening on the surface of the oil to cause concern that something was wearing badly in the engine/gearbox (particles must be so fine that they pass through the paper oil filter !).
Changed oil and filter, did ~100 miles, dropped some oil out and there was still visible contamination (of aluminium) in just a small amount of oil.
Engine out and strip down commenced.
The only worn part I can find is the pressure plate (cover) of the Yoyodyne slipper clutch, as per pic’s.
Slipper clutch fitted at 10500 miles, last oil change 16700 miles when contamination found.

DSCF2179.JPG DSCF2178.JPG
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I have seen complaints on a Suzuki SV650 forum about Yoyodyne slipper clutch pressure plate wear, but on the pressure surface and not the ‘base’. Many arguments pointed to the Black anodising not being hard enough.

The original clutch pack is going back in, as I don’t need a slipper clutch for riding on the road.
 

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I have a sigma slipper clutch on my gixxer race bike (looks similar to yours) and get similar sort of wear on the spring holder tunnels but not quite as bad as the burrs you are getting. Was the slipper assembled correctly with correct pack clearance, it looks like there is to much rotational movement of the outer pressure plate as it lifts to slip? Another thought, what type of friction plates are you using, Ive seem similar high concentrations of ally in oil when using plates that have ally embeded in the friction material, I know EBC do those type of plates and when used in a slipper clutch will produce worrying amounts of ally in the oil.
 

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If you don't align the oil pump gear with the teeth on the back of the outer clutch basket, then the gear will be pushed inwards, and will grind the casing away when the bike is started. This probably sounds like a screeching noise for a few seconds which then clicks as the gear teeth are forced into alignment.

The damage is done by this point.

It may also crack, meaning danger of sudden oil pressure loss if it lets go.
 

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I've given up with slipper clutch upon RC8, I didn't like the less motorbreak and besides the risk of ruin a perfect engine is always there. I've seen enough blown clutches fired tru the engine casing on trackdays or race events. Remove that judder spring if U rebuild clutch, it will tear down and break into little pieces of mayhem becuz of the friction. Maybe search for a new engine, maybe LC8 1190 or something. Change is that the internals from crack to pistons are ruined.
 

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Discussion Starter #5
An update for those that maybe interested...

I have found more Slipper clutch wear, as per pic's.

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The depth of the 'worn' section is approx. 0.38mm
The 'worn' section has also caused pick-up in the friction plate and somehow there is scoring (wear) on the steel separator disc (which was adjacent to the buggered friction plate. Buggered friction plate only buggered on one side though) :-

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I only noticed this when I was transfering (and cleaning, and measuring) the plates and discs from the Yoyodyne assembly onto the KTM original clutch basket. Replacement parts ordered and fitted.


Thanks for your comments....
The Yoyodyne slipper clutch was installed as per Yoyodyne instructions (though they were in poor pigeon english with out of sequence and un-identified pictures) and required several read throughs to properly understand the inner plate, disc and ring assembly order).
The engagement of the oil pump gear was correctly done - the rebuild now has the latest machined gear.

TTFN
John
 

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Interesting to see the wear. Did you buy it new or used - have you contacted yoyodyne about it?

I've not tried Yoyodyne myself so can't really add anything here. I ran a Sigma one in my R1 for years and hammered that on road and track for years without any problems.

The '09R I bought last year has the powerparts one fitted and so far I've not touched it apart from to loctite the 6x clutch spring bolts.

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