I have just replaced the clutch plates in my 1982 SWM 320 with some new surflex plates. I am using 6 friction plates and 7 metal plates and have put all six medium springs back in the clutch basket. I am using ATF in the gearbox.

However I need some help, the clutch is slipping like mad, even in 2nd gear and I can't figure out why. I must admit I was confused as to how many plates I should use as I have numerous clutch diagrams showing anywhere between 5 and 7 friction plates. Engaging the gears is really smooth with the new plates installed so what have I done wrong? Any help is appreciated.

Cheers

Chris

Have you checked / adjusted the screw behind the plastic cover just in front of the kick start ?

(The 1980 parts book shows 6 friction and 6 steel, 5 @ 1mm 1 @ 1.5mm. Climber shows 6 friction 5 steel, for what it's worth)

I use 3 of the lightest springs and 3 medium, doesn't slip untill you drop it in 4th, I also currently use 5 30 oil.

Edited to show correct no of plates.

Edited January 26, 201412 yr by b40rt

Thanks B40, I checked the adjuster and everything seems fine. I' be got around 2 to 3mm of play at the arm. I am at a loss as to what to do, the springs seemed ok when I installed the new plates. Maybe I need to add another friction plate?

Part no for the 6 friction, 6 steel basket is 292 180. Can you measure the thickness of a barnet plate, I will find a standard one to compare.

Edited to show correct no of plates.

Edited January 26, 201412 yr by b40rt

Take a look at the following, its the SWM 240/280 clutch set up

You will see there are -

6 x Friction plates

5 x Metal plates - 1mm thick

1 x Metal outer plate 1.5mm thick

I have found that the Sureflex kits do not run exactly the same thickness plates as the standard Rotax.

Easiest thing to do is measure the combined thickness (stack height) of your original plates and compare it to the stack height of the Sureflex ones you have fitted. If its slipping, my guess is that the Sureflex plates will be a lower stack height than the originals.

Martin, have you swapped a later clutch centre (missing out the last plate presumably) into an earlier clutch ?

Ross, there are about 4 different clutch centres an 3 different depth baskets, Add to this the washers either side of the centre bearing on the clutch......same thickness on most 320's.......one thick and one thin on 125's, some enduro 250's and some of the early 320 Guanacos........which is 1mm difference and the same as a metal plate.

I have tried pretty well every combination of the above, there isnt any that make it better, plenty though that make it worse.

Stick with the standard set up where possible.

...

I have tried pretty well every combination of the above, there isnt any that make it better, plenty though that make it worse.

Stick with the standard set up where possible.

When rebuilding the engine of my 320 we made the same experience, the original set up of clutch plates works best so far. Which doesnt mean that there isn't a way to improve it. I still believe that most force that has to be used for engaging the clutch is needed for the particular actuating ...

Thanks for all the advice guys. Martin you are right I have just checked the height of the stack and the Surflex comes up a lot shorter. I will need to add another surflex friction plate and metal plate to get it comparable. That will teach me for buying cheap! (I got the surflex for £30 from a friend, new still in the wrapping) I will reinstall tonight and see how it goes. I am still planning on using all six springs and ATF. Does anybody recommend a different oil? I hear PJ1 Clutch Tuner is supposed to be very good.

Just saw this, using 5:30 semi synthetic. Good with an Aprilia clutch/ outer casing.

Just thought I would post the result of trying numerous combinations of clutch plates and springs on my 1982 SWM. I have fitted a surflex clutch plate kit in place of the standard SWM clutch plates. Through trial and error I have now got a really light clutch and no slippage in first three gears and very little slippage in 4th gear. So in terms of clutch plates, my stack starts off with three 1mm metal plates followed by 6 friction plates separated by five 1mm metal plates and one final metal plate of 1.5mm. I am running 4 mediium springs and have fitted a clutch lightener arm similar to the Jumbo underneath the tank. It's taken me two months to get the combination right so hopefully this post will help others in the future.

Just curious if the clutch slips with new plates, why have you stayed with the 4 springs?

Hi Chrisb1504,   just for info, were the Surflex plates you used the kevlar mix or the sintered ones ?

 

Thanks,

 

Phil