Scooterotica

Hi all, i'm having a few problems with clutch slip. I'm using an MB crownwheel and basket, Tino spider with 6 plates. There is plenty of space between the steels and plates when compressed and the top plate is not rubbing on the kickstart shaft. I'm i right in thinking that the spring on the drive sprocket can cause slipping? Any ideas or advice would be a real help. Cheers Pete

i checked my front sprocket for slipping by assembling it without a spring and there is no way they can ride over each other.
what plates you using and with what oil?

I'm using surflex b plates with ST 90 Rockoil.

bingo

What is the engine spec and what springs are you using? If you can measure the spring free length, compressed length, exact number of coils, wire diametre and spring diametre I could work out the clutch preload for you.

Does the clutch slip on kicking over, acceleration, gear changes or all three?

If you have mixed and matched different clutch components together it is more likely that you don't have the correct spring preload, than a problem with oil. You don't have to be far out to have a significant loss in preload. 1mm less preload on a 20Nmm spring 100Nmm less preload, typically a standard clutch is 550N preload that is almost 20%.

It is an Imola with JL 3 Franspeed pipe, 28mm Mikuni, Ducati light flywheel, LI 150 box 16 X 47 sprockets, MB basket and crownwheel and springs, Tino spider, Surflex B plates. It made 17 BHP on JB's dyno but was slipping so much it has more to come. I used the original drive spring. I'm not sure which spring /springs i should measure. It does sometimes slip when i kick it over but the top plate is not rubbing on the kickstart shaft. Cheers Pete

If it slips when you kick it over you either don't have enough spring preload or the mechanical assembly is compromised, like a steel slipping of the bottom of the spider and jamming. This is the age old problem of mixing and matching bits together.

Rich_T wrote: This is the age old problem of mixing and matching bits together.

I agree totally with you Richard. I should in hindsight have bought a complete clutch from one manufacturer, i love the look of your clutches but they are a bit out of my price range i'm affraid. Looks like i'll have to strip the clutch down again. Thanks for your time. Cheers Pete.