Gearbox again - SBS125

Hi all,

still having problems with my box so changed the oil and things improved but the problem still comes up when quite hot. So decided to investigate the clutch and actuating rod condition. I've undone all the obvious bolts holding the clutch cover on but the thing won't budge. I notice that the kick-start shaft goes through the cover - is it anything to do with that or should it just slide off? Or do i need to do anything with the speedo drive? Failing that do i need to just give it a good whack?

Thanks in advance.

Phil

I believe your engine is very similar to Hondas CG125. There's a service manual you can download here:

http://www.megaupload.com/?d=GP2PJ9WL

or here:

http://www.mediafire.com/?5mlg11z9pz3

If those downloads don't work just google these exact words:

Honda CG125 76-91 service manual.pdf

From what you've described I would now whack it with a mallet or a hammer through a block of wood. They sometimes stick on. Once the joint is cracked open, withdraw the case evenly a little at a time and try to save the gasket. If it remains either on the crankacase or on the cover it'll be OK, but sometimes it sticks half on one side and half on the other and it'll tear.

right - got the case off. Couldn't find my rubber mallet but a block of wood seems to have done the job! Now the casing is off i can see the clutch. The whole lot seems to wobble around quite a bit. If i remove it how will i see if it's worn or does wobbling around point to problems already? Also, i experimentely pushed on the rod quite hard to see it work and it wont budge - is this normal?

Quote:

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Originally Posted by Phil007

i can see the clutch. The whole lot seems to wobble around quite a bit. If i remove it how will i see if it's worn or does wobbling around point to problems already? Also, i experimentely pushed on the rod quite hard to see it work and it wont budge - is this normal?

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I think it's meant to wobble a little bit. If it's anything like the CG125 it's only held by just a circlip in the centre.

I don't think you'll be able to lift the plates against the spring pressure just by pushing against the pushrod, not without the leverage provided by the handlebar and clutch-end levers.

You'll have to remove the clutch cover plate and the springs, and withdraw the plates one by one. Note the order they come out.
The push rod should now slide freely to and fro.
Measure the thickness of the friction-lined plates for wear. They should not be thinner than 2.6 mm.
Measure the clutch spring free length, it should be about 35-36 mm, and all springs the same legth.

Place the plates one by one on a flat surface like a piece of glass or similar, and check for warpage. Maximum warpage allowed is 0.2 mm measured with a thickness or feeler gauge.

Once you can see the whole clutch drum or basket, inspect the "castellations" for burring or indentations. The surfaces where the plates slide should be smooth. Same goes for the splines in the inner rotor.

By the way, you have checked that now that it's free, the clutch cable operates smoothly and that no strands are frayed and creating undue friction?.