Burning clutch plates out...Now with Photos

[Dazza]

What would cause a clutch to burn out a set of cork plates and 2 sets of carbon plates within a few hundred miles at a time.

The engine is quite highly tuned- reed valved, matched parma 177 but not ridden hard all the time, the clutch is a banded cosa with updated springs, I hear that the basket needs to be 21/22 mm deep but would have thought if this clutch was 18mm that drag would have been more of an issue not slippage?

The cable adjustment was fine with a slight bit of slack at the lever.

We are changing the plates to cork again tomorrow but we would like to know what the cause is

[H,POOL GADGE]

Mmmmm! good question! we've heard of the basket going, but burning out, lets think! the clutch is a wet clutch lubed by oil, are the oil ducts clear, no oil would mean friction and and then burnt out, but definatly do the turrets to 22mm on the basket, doing this would ease the constant pressure the plate are under from the upgraded springs and may promote easier lubing plus easier on the clutch lever, i bet your turrets are 18-19mm now!

[scooter perv]

I rebuilt a mates scooter and fitted new corks and old steels 3 plate (it previously had a 4 plate). The clutch wasnt right, it bit at the last 2cm of clutch lever and after 500 miles its burnt out and slipped like buggery. I put the old 4 plate back in as it was off to rally next day and it was perfect, bit when you let the clutch out when it should and didnt slip..and that was from just changing the plates and steels...oh and new dr competition springs.

[Dazza]

As you can see the tabs of the plates are well bent after only a few miles.
the turret measurement is 14mm - the welded band taking up around 5mm but would this cause it to slip??

Plenty of oil in there as well, we are going to fit a new set of cork plates in case its a dodgy 2 sets of carbon plates (newfren btw)

Sorry struggling to get my head round this...

[goldeneye]

the turrets on that look like 19mm. machine them down to 22mm dazza (left hand side of foto, if you get me drift) new standard plates AND steels (this months scootering has a good article on vespa clutches) clean the gaps in the friction material out, and just use SAE30 oil. personally i"d buy a standard LML clutch from beedys, they are only about 40 and a bit quid, and ive fitted a canny few, and they work great. let us know how you get on. that tang on the plate in the picture looks f@@ked after a couple of hundred miles. (try Newfren plates)

[philhnottm]

the turrets on that look like 19mm. machine them down to 22mm dazza (left hand side of foto, if you get me drift) new standard plates AND steels (this months scootering has a good article on vespa clutches) clean the gaps in the friction material out, and just use SAE30 oil. personally i"d buy a standard LML clutch from beedys, they are only about 40 and a bit quid, and ive fitted a canny few, and they work great. let us know how you get on. that tang on the plate in the picture looks f@@ked after a couple of hundred miles. (try Newfren plates)

Goldeneye

The plates fitted first time were cork they lasted 17 miles
2nd set were Newfren with FA italia springs lasted 100 or so miles
3rd set again Newfren carbon fibre with SIP XL springs lasted about 57 miles before being chewed up again.

I had a same (cosa) clutch with cork and FA springs fitted to another scoot Mallossi 210 at the same time and thats done around 4K without any problems and has a lot more power???

Its been suggested the Cush drive may be causing the problem??
And the depth is about dragging not slipping????

(good job dazza knows what hes on about , im the spanner passer !!)
Regards

Phil

[H,POOL GADGE]

gadge, what i,ve experience'd on cosa clutch 'n' 19mm turrets, on tickover the scoot would creep, adjusting clutch zero and would bite at the end of lever being released also bite with a snap thus chewing the lugs on plates, my thinkin is 19mm turrets is like having a lazy clutch foot in a car(dipping the clutch)the clutch is never fully released...double check engine oil sae30, turrets 22mm, lugs sliding past that band and clutch arm moves freely....can't think of now't else! good luck....

[Dazza]

Well....newly assembled clutch fitted, engage gear, clutch out , no drive....
Clutch cover back off and the circlip has popped out!

I had checked the circlip was well seated and the joint within one of the turrets, double checked and fitted , it had popped off on tickover.

The circlip flicks out with the slightest of flicks from a scewdriver its as if the upper lip of the basket is not wide enough or the groove isn't deep enough. The circlip is a lot thinner than the groove which allows for a lot of play laterally.

I think maybe the circlip May have partially popped out on Sunday causing the slipping, thinking back now when i levered the clutch out it did pop apart confirming the circlip being partially seated.

Bloody thing..I've suggested Phil follows geoffs advice above and buy the lml complete clutch and start from scratch.

Not overly impressed by the cosa clutches

[OzOAP]

Not overly impressed by the cosa clutches

Fit an earlier style. I never fit Cosa type to any of my tuned P Ranges

[philhnottm]

Latest update

New cush drive fitted.Today

brand new lml clutch used - failed
brand new old style vespa clutch used failed
new cosa clutch used with newfren carbon plates and strong springs-failed
Also tried with cork springs same result.
cosa clutch with xl sip springs and turrets dremmelled in depth as per previous suggestions .
clip is still flying out despite being bonded.
2 different cosa's (both brand new also not solved the problem)
Runs fine at slow speeds soon as its given some wellie clutch goes again.

Appear to have sorted the clutch plate eating issue need the clutch to say together now under power

Just orded a SIP re-enforced basket -losing the will to live !!!