Modern Vespa

Hey guys I know this has been discussed a bazillion times but I have a SIP sport clutch that when changing gear feels and sounds like it doesn't disengage the drive. Took it out and the 3.8mm thrust washer to fiddle with it. I have also a 0.8mm and 2.8mm washer and individually and in all combinations when installed I select 1st gear and the engine stalls! Corks soaked Lever slack taken up and cable adjusted no bueno. It's as if there isn't enough separation when pulling the lever. I guess the washers move the whole basket out so how come with all 3 giving like 7.4mm of outwards movement I still cannot get the required pull to disengage the plates? Also looks like the square basket teeth have started deforming somewhat as the plates rotate slightly in the basket. Is this normal? Thanks in advance.

Pictures please. So we know exactly what you have. How free does it spin when it's out, compressed and in your hand?

Which clutch is it?

108 SIP costa race clutch banded basket. [/img]

Jack221 with the compression tool fitted can you spin the plates? I can hear them rattle loose with about 1-2 mm of compression.

Did you check the clutch cover actuator and brass plunger?

If the arm or brass plunger is worn, you won't get any separation of the disks.

I imagine the clutch is new with new clutch springs?

108 yes the clutch was new 300 miles ago and just running a new cylinder set in so no thrashing. The pressure plate and brass plunger are both new also. I have the old one so will compare at The Weekend. The bike also drags when in 1st gear and clutch pulled in.

Pressure plate is usually pretty robust, so that's never a worry.

I would check the actuator arm and see if it's not too worn down.

Another thing to check is pulling the clutch lever at the handlebar and kicking the kick start lever… and seeing where the bike point is.

If it's never loose spinning and always starting the engine, I'd take the clutch out and check it's assembled correctly.

Soaking clutch plates is overrated. So it's not that…

Two things to confirm.
The steel plates have a correct order; thick one in first, notched one, then other two. If the order is wrong the clutch drags.
Check the friction plate outer tabs are not catching on the basket band, in any way. Hand file off any interference.

Thanks Jack I'll have a look this evening once I pull it out. I'll get picks too.

Did you changed crankshaft for something "sport" or "race" one?

I was met a problem when pressure plate is touched shaft. It was on LML cases with Mazzucchelli full-circle crank shaft and the same clutch as yours.

On the other side I have same clutch and Mazzucchelli rotary crankshaft and never have any problems.

There is a well documented problem with aftermarket cosa clutches. There is not enough room for the plates to separate properly resulting in clutch drag. The clutch will drag more when it is warm than cold. There are two issues at play the clutch turrets are not deep enough (22mm from memory) and the plates used are thicker than standard.

I don't have many nice things to say about sip branded cosa clutches. I have had to fettle mine to make them work.

Check that this is not your issue.

Cheers

MattO

Grimm I think you have hit the nail on the head. I have used 3 different spacers and their combinations and the bike stalls. Took the clutch apart after filing the tangs to extract the inner plates from the banded reinforcement. These tangs were pretty beat up after about 300 miles so worried about longevity as well as getting a decent gear shift. Any feedback from SIP regarding this anyone?
The clutch rotates when compressed but doesn't spin it does take some hand torque to move it. Thanks guys

Jack221 Plates were in the correct order. Maybe SIP need to reduce the thick plate by 1mm to aid separation.

The tabs on those plates are beat to hell, especially for only 300 miles. Is it just that rough to shift???

I'm assuming it's not anything too crazy, build-wise, but even if it was, that's a LOT of wear for that few miles.

Chandler man just a Pinasco 177 kit on it mate and running in around town haven't had it wide open or ragged it at all. Bought the clutch from Scootermercato so asking David how to return it at the moment. I had to file the tangs to get the plates out of the basket.

When the clutch drags you beat the shit out of your tabs in a very short space of time. When you cure your drag issues the tabs last a long time.

Cheers

MattO

Yeah stock plates don't last very long.

And with your clutch issues, it'll be even shorter.

Below is a photo of stock plates on a malossi 210, no problems with disengagement, 3 weeks of city stop go riding, around 15kms a day.

Whats the alternative to stock? Carbon or harder plate material?

CR80 type plates… ran them for years… seem bulletproof.

Swapped them once in 6-7 years just because felt like refreshing them.

A Pinasco 177 is not putting out enough power to worry about a fancy clutch. A stock seven spring will cover you just fine. If you're worried about it mushrooming or slipping, put a band and some stiffer springs on it.

I think I have the SIP Performance clutch in my 200 motor and it's been just fine, so maybe the clearance issue is limited to small block motors?

Looks like the tangs were touching the reinforcing band. As soon as this happens the clutch doesn't work. The teeth on the inner steels are worn out too. Those clutch plates are the cheapest garbage. And that's where they should go.

Get a set of these. And they'll last a very long time.
https://www.sip-scootershop.com/en/product/clutch-friction-plates-sip-performance-cosa-2-sport-cr80-race-clutch-cosa-2_93081900

MattO
How did you fettle your plates? Did you take material off of the corks or the steel plates? Cheers Andy

Step 1. File the turrets in the clutch basket to a depth of 22mm

Step 2. Throw the original plates in the bin

Step 3. Buy an original set of Piaggio plates or as Jack mentions a set of CR80 plates

GrimmMattO
Thanks for the info. Got the order on for the cR80 plates and now I'll go do some whittling
Cheers Andy

i have the same clutch and i dont use the small brass plate,and it works great...otherwise it didnt work at all..

I hope something got lost in translation about not using the small brass plate

Just as a FYI to everyone, the cR80 friction plates don't fit a clutch with the reinforced band as the tangs are too wide to slide down the basket castellations. If I decide to use then I'll have to grind away the extension to the tang away. Cheers Andy

Who told you scooter parts fit out the packet
Quickest way is to put the new CR80 clutch plates loose in your old unbanded basket. And file all 4 at once flush with the outside surface. 10 minutes max. Fit like a glove.

Jack thanks for the tip. I'll have to bandit the old basket to hold them as it mushroomed causing the clutch r&r in the first place! Cheers

Same clutch. SIP CR80 plates fitted without any problems.

Roland got my plates from scooter center. Mmmm?

Ah yeah, forgot about that…

Keep assuming everyone is running a big bull, modern style cosa clutch basket.

Yeah the original cr80 plates won't clear the reinforcement band. The SIP plates Roland mentioned has the right clearance. They're shorter.

108 got the Dremmel out and they fit now!

Assuming you brought a set of pre modified Honda CR80 plates. These are fine but always need extra manipulation to fit nice.

The suggested SIP plates are made to measure
https://www.sip-scootershop.com/en/product/clutch-friction-plates-sip-performance-cosa-2-sport-cr80-race-clutch-cosa-2_93081900

Anyway, at least you're done now. Put in one new 3.8mm washer and take a picture. Won't be seeing it for a long time.

Jack you are not wrong there mate. She's like new now. Cannot believ how I put up with that for 300 miles! Thanks for all the advice guys appreciate it. Andy

That's awesome to hear you're now sorted. Bad clutches are both super-annoying to ride and also really hard on the rest of the motor.

And remember: NSM...come for the mechanical advice, stay for the snark and illegal ham casino.