650 Clutch Woes

[G0FHM]

Hi Guys,

I've recently split the cases and fitted a lower mileage gearset/forks/shift drum.

I've bought a new friction plate set (and HD springs), as the old one was just about shot.

However, the clutch won't bite!

I can turn the inner drum by hand when the bolts/springs are tightened up!

Everything is assembled as per the factory manual (and the exploded parts diagrams). The input shaft protruding is the same length as the old (from the bearing inner race to the end of the shaft is 72mm on both).

Looking at the cover plate through the holes, it appears that the cover plate is in contact with the inner drum.

It would appear at first glance that there aren't enough clutch plates, but there are 8 friction plates and 8 driven plates (well 7, as one is held in place on the drum with the piano wire clip).

The service manual states that the lower limit for the friction plates is 2.4mm, and on putting the digital vernier on the new ones i'm only seeing 2.8mm - That's only 0.4mm wear range!

The metal driven plates come out at 1.5mm, and don't look visibly worn (although there is no minimum thickness specified in the manual).

I'm all out of ideas, apart from maybe the friction plates are wrong. The clutch kit is an EBC CK3330, which apparently is for the GX/GZ 1981/82. It fits in the basket ok, but I'm wondering if the plates aren't thick enough? (ie the wrong parts in the box?).

I'm at a total loss - I've had father in law check everything out, and even he is scratching his bald patch! He normally has the ability to see through things, and make you look a total bonehead in the process, but no such luck!

Any ideas?

Thanks,

J

 

[Steve]

Have you adjusted the cable and helical gear on the other side of the engine? :-k

By the way, you are going to regret those "HD" springs about 5 minutes after you start riding.

Unless you are drag racing with a built-up engine, there is no need for anything stronger than new OEM springs.

.

 

[tom203]

Does your setup look like this ? This is my unmolested (in theory) spare clutch

 

[huntb]

Have you adjusted the cable and helical gear on the other side of the engine? :-k

.

Adjusting the cable? He has the cover off and is spinning the inner basket by hand.

OP do you have items 8 and 6 installed from the parts fiche? The wave washer and seat.

You also might want to find some OEM springs like Steve said. I have 3 OEM and 3 +15% HD springs in my 650 and its perfect. When I tried all 6 HD springs I almost had to have two hands to pull the clutch in.

 

[G0FHM]

OP do you have items 8 and 6 installed from the parts fiche? The wave washer and seat.

Yep, all intact - That hasn't been disturbed. It would appear to be working, as the wave washer is pushing the driven plate hard up against the piano wire clip (ie no loss of springiness).

A rather alarming update:-

I've measured the new plates, and they all come in between 2.80-2.89mm thick.

I've dug the old plates out (which were visibly fairly worn), and the first one I have measured, is 3.06mm!

Multiply that difference by 8, and you have a fairly large gap!

I'm wondering if EBC have made a boo boo... Wrong bits in the box!

J

 

[G0FHM]

Well, according to EBC, their plates are made to spec, which is 2.80-2.89mm.

I'm wondering if something is different within the clutch assembly itself?

Looking at the clutch components, I have the following markings:

Primary drive/Basket: -2 310 (Suzuki part 2120034201)

Drum: -1 451 (Should be Suzuki part 2141145100)

Pressure plate: -3 451-2 (Suzuki part 2146245102)

I can see a pattern with the drum and pressure plate, with the 451 appearing in both part numbers.

I've trawled the Suzuki parts fiches on cmsnl.com, and can see nothing for pre '90 models that feature 310 in the part numbers for the clutch basket.

Something isn't right still... But I can't find what it is!

J