New baby stiff clutch operation

[starfield181]

I said that theer would be more posts as I worked through my newly acquired M14 250CSR. All oil levels topped up as per guidnace, not a lot needed but at least I know where I am starting from if I do get leaks etc. No smoke when I started it up this morning which was good. Not sure how relevant it is to current issues, but the club dating certificate reports that it was shipped to a delaer in Hull on 13th October 1965 which would I imagine make it a 1966 model.

Anyway, the only thing stopping me from riding it (excluding the freezing weather) is the very stiff clutch action. I have oiled the cable (New) and adjusted the clutch end as per the book then the free play at the handlebar with the in-line adjuster. It is certainly a bit easier but not as light as I would like it to be and the heaviness seems to me to be in the clutch itself rather than in the lever/cables. One thing which may be relevant is that the clutch lever is new from AMOC spares and I am not convinced that it is giving a straight pull.

I had a similar problem with my Sunbeam S8 and turned a gorilla action clutch into a smooth and light clutch by re-drilling the pivot hole of the lever so it was closer to the pivot point of the cable nipple. This increased the leverage ration at the expense of reduced movement of the pushrod but the clutch still cleared well enough for clean gearchanges and finding neutral. However, before I try this are there any other things I can do with the present arrangement?

many thanks

PeterF

[Ozmadman]

They are a bit stiff in operation anyway I think and when I first got my bike I could only ride it a short while due to severe wrist pain. Over time I have gotten used to it and hardly notice now. Mine got a bit easier after my engine rebuild but I think even now I could do with tightening up the springs a tad as sometimes I get a slight bit of slip ( I think) on hardish acceleration even though the adjustment is correct. Having to drain the oil and remove the case is a bit of a bind though so that's another job for the warmer weather. You could try slackening off the springs a bit and make sure the cable had a smooth kink free run down to the box

[alanengineer]

you might find you have reproduction levers that have the wrong pivot centres, causing a stiff operation. I cant remember the original distance.

[clanger9]

Is the operation 'sticky' or just heavy?

When I rebuilt the clutch on mine I found heavy wear ridges on the three spring cups that were catching on the holes in the clutch centre. This made the clutch feel sticky and 'gritty'. Replacement cups don't seem to be available, so I just cleaned up all the ridges and now my clutch feels very smooth and light. Maybe worth a try?

[Janet]

Replacement cups don't seem to be available,

The club spares sell them, although they're currently listed as stock being limited.

[SPRIDDLER]

smooth and light clutch by re-drilling the pivot hole of the lever so it was closer to the pivot point of the cable nipple. This increased the leverage ration at the expense of reduced movement of the pushrod

I don't know about L/W but the correct distance on H/W is 7/8" pivot bolt centre to nipple centre.
It could be that the clutch springs are screwed in more than necessary.
A good test to locate the source of the stiffness is to fit the clutch cable (for trial only) in the most sympathetic route. This usually means having it trailing from the h/bar and outside everything. If the clutch action is significantly lighter then the cable friction isn't helping.
Most modern cables are Teflon lined and should not be oiled (according to my preferred supplier, Venhill Cables).
The cable conduit (the outer) on cheap and not so cheerful cables can crush or distort on bends producing resistance.

[starfield181]

Thanks for the tips on clutch action and adjustment. Adjusting the clutch itself, oiling the cable which seems to be a Doherty type without nylon liner and making sure it has as smooth as possible a run seems to have helped. It is still stiffer to operate than I would like but I can live with it for now. Don't really want to start dismantling things any further yet unless it proves essential. If weather stays dry today I hope to have a first test ride.

[Ozmadman]

Probably the best you will get and before long it will become normal. My 1974 Yam RD 250's clutch is silky smooth and light, trust the Japs to get it right. Did you go out on the test run??

[Janet]

My 1974 Yam RD 250's clutch is silky smooth and light,

My 250 Honda is like that.

trust the Japs to get it right.

Not always. My Honda 400/4 has a clutch and throttle which are so heavy that after a year of riding I could almost crack walnuts with my bare hands. Later, when I pulled in the clutch on the 250, it was so easy I thought I'd broken it.

[starfield181]

Going back to an earlier reply, I measured the distance between nipple centre and pivot screw centre on the M14 and its 25mm or 1", The distance on my G5 is nearer 30mm. Both clutch levers are new aftermarket items supplied by AMOC. The M14 one is just a lever but does have a ball end which I like, the G5 has the decompressor built-in and the lever end is plain. If 7/8" is the correct figure its no wonder I find the action stiffer than I would like. The old levers are in the box of spares which came with the bike. Will measure them tomorrow.

Hoping for a first test ride on both bikes tomorrow as I have to get kitted up for a lunchtime jaunt anyway.

PeterF