Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > clutch 620ss

[MadMostin]

my 620ss clutch is slipping like a slippery thing, checked plates and the corks are within tolerance. The steels are blue. I then whipped out the clutch on my spare motor and that is pretty much the same, blue steels? the pack is .5 mm thicker.

The springs have two preload washers, giving an extra 3mm worth of spring pressure.

Anybody know what pack thickness should be?

steels are 1.5's

[Chaz]

Originally Posted by MadMostin

my 620ss clutch is slipping like a slippery thing, checked plates and the corks are within tolerance. The steels are blue. I then whipped out the clutch on my spare motor and that is pretty much the same, blue steels? the pack is .5 mm thicker.

The springs have two preload washers, giving an extra 3mm worth of spring pressure.

Anybody know what pack thickness should be?

steels are 1.5's

What oil are you using?

[MadMostin]

Originally Posted by Chaz

What oil are you using?

Motul 5000 semi synthetic.

Remembered what you told me Chaz and kept the fully out of it.

This aint the motor i had off you, thats got the semi slipper jobby installed.

Did notice a quantity of silver instant gasklet on the pushrod so i suspect that wont have helped although the spring pressure should of overcome this?

When i was riding the bike it seemed that with only the slightest amount of pressure on clutch lever would result in slippage.

Gonna order a 2.0 mm steel today. Could be barking up wrong tree.

Help always appreciated chaz and ive lost your number otherwise i'd have been calling you, anything im messing with now, you've no doubt got the t shirt for.

[skidlids]

On my intial venture into the 620 class I had a slipping clutch problem dispite using Semi-Synth, My cure has always been to replace a couple of the 1.5mm Steels with 2mm steels and replace 3 of the standard springs with 3 from a 916
I did buy a set of Surflex clutch springs to fit but Matt Larrett borrowed them at Donington in 2009 at the Moto6 round and I haven't seen them since

[paynep]

Originally Posted by MadMostin

The steels are blue.

Ditch them! The only time I've ever had clutch slip in 5 years on a 620 was before I replaced the plates, and I've used Shell and Rock oil over the years.

Actually, no I've changed my mind - just before you go out in qually at Mallory, I recommend you pour a bottle of Slick 50 into your motor....

[dunlop0_1]

Originally Posted by skidlids

On my intial venture into the 620 class I had a slipping clutch problem dispite using Semi-Synth, My cure has always been to replace a couple of the 1.5mm Steels with 2mm steels and replace 3 of the standard springs with 3 from a 916
I did buy a set of Surflex clutch springs to fit but Matt Larrett borrowed them at Donington in 2009 at the Moto6 round and I haven't seen them since

All the clever people with a 620 have a dry clutch fitted.

[Chaz]

Originally Posted by dunlop0_1

All the clever people with a 620 have a dry clutch fitted.

You must be the only clever 620er then

Not had a problem with any of my 620's with wet clutches & never put any new plates in 4yrs. Bet they don't last that long in a dry clutch