SR125 New clutch frozen

[dopplerhire]

Hi all,

I recently purchased a 1986 Yamaha SR125 SE and managed to get it running through some excellent forum advice - cleaning carb/fuel tanks etc...
After a few weeks it was apparent that the clutch was slipping and so I bought a new set of friction and pressure plates.

I put them on, on the weekend and it ran like a dream for the first day. Towards the end of the ride the bike becamse jerky until i got it home and realised that the clutch seems frozen - I can't get it into 1st gear. After some cable adjustments, the gear shift now lets me change up a gear with no clutch, but I can't get it into 1st (engine off)!

I'm thinking that maybe I should have done some adjustments at the clutch basket before the crankcase cover went off; or maybe the plates are stuck together. If so, could this be anything to do with the oil I used - a local shop adised on the oil and the manual said to lightly coat the friction plates in oil before refitting, but perhaps the engine oil is of the incorrect type (haven't got the details on me).

Any advice appreciated - I'll probably be taking it all apart on the weekend but don't want to simply unfreeze the plates for the same problem to happen after it's refilled etc.

Many thanks

[Big Pete]

sounds more like an adjustment problem, maybe the lock nut on one of the threaded adjusters has vibrated loose and the lever travel isnt actually operating the clutch mechanism.
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[Ichy]

Some bikes I've worked on have a adjustment on the clutch push rod, maybe it needs resetting with the new plates in?
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[stinkwheel]

How does it feel on the lever? Is it loose or can you feel the lever pushing the clutch springs apart?

[finpos]

It's often recommended to soak new friction plates in oil overnight before fitting them. Don't know the reason for this particular bit of folklore, but I've always done it. Even if you used the "wrong" oil, I doubt it will have had an effect so quickly.

Another possibility is that you broke your clutch basket because you didn't do all the bolts up evenly. That gives some very strange symptoms indeed

If you are taking the cover off for a quick look, it's sometimes possible to lean the bike over enough so that you don't have to drain and re-fill the oil. Don't try it on your best carpet, though.

finpos.

[dopplerhire]

Some useful comments - thanks.

Without looked any further, all I can add to this is that the clutch lever seemed a bit loose so I adjusted at the cable both at the handlebar and by the spring lever on top of the crankcase. No matter if I tightened or loosened, there doesn't feel like any clutch plate release. A bit strange how I can shift up 2-3-4-5 without any clutch in and not 1st - or is this normal?
I hadn't gone for the soak in oil overnight approach as the guy in the bike shop advised against - but I did lightly rub in oil as in the Haynes manual.

In the back of my mind, there was an adjustment bolt sitting on the outside of the basket after I tightened the springs up. I can't remember whether I tightened this before sticking the crankcase cover back on, or whether I needed to?

I suppose there's a chance that adjustment needed to be made here first, but would the symptoms agree with this? i.e. seemed fine for a 1/2 hour commute to and then again from work, only to have no clutch at the end?

I'll be opening it all up again on the weekend so an "order of priority" approach would be appreciated on what to check.

Thanks again

[finpos]

Sounds basically like your clutch isn't working. The 2-3-4-5 Upshift is pretty normal, you are doing clutchless shifts. Getting it in and out of 1st is a different prospect with a busted clutch.

There should be another aduster for the clutch at the end of the lever outside the crankcase. I'm a bit skeptical about there being an adjustment inside, but you never know. The haynes manual will have definitely mentioned it. As long as you've adjusted things at each end of the cable so that you have a mm or two of free play at the lever, than that's all you can do.

Frankly, for it to go from working fine to being broken that quickly, I'd expect something mechanical inside that cover to have gone wrong

finpos.

[Big Pete]

on some clutch actuator systems there is a cam type thing inside the cover that pushes the clutch centre, they have a nasty habit of getting flipped over during reassembly if you arent aware of it and theres no clutch when its all back together, might be worth a look.

BTW, you dont have to drop the oil to check the clutch, you can lay the bike over on its side on some old blankets/cardboard boxes/foam etc and just take the cover off, the oil will all be on one side of the engine and wont run out. It saves loads of time on that sort of job.
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[dopplerhire]

Just wanted to thank everyone for their help - my bike is now back on the road.

As suggested by the replies I recieved this indeed turned out to be an adjustment problem. On the pressure plate (outside,spring side), there was a little locknut and threaded screw. The locknut needed undoing and screw turned in until the clutch release lever lined up with a mark on the crankcase cover.

This wasn't possible using the adjusters on the outside of the engnine so had to remove crank cover.

Good advice for not having to drain and refill by lying bike on it's side. This worked a treat and I was thankful for the time saved given the torrential rain on the weekend.

Overall took me about 3/4's hour after fiddling with the various adjusters - not too bad!