Mk111 Heavy + Dragging Clutch Advice Please

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I've had Venhill nylon coated clutch cables and I don't know if I put too sharp a bend in it, but the cable partially cut right through the nylon and jammed the cable making it hard to use. This happened a couple of times, forcing me to renew the cable.
 
I double checked with a digital scale rather than the spring fish scale I used years ago when the clutch improvements were made.
The digital scale showed 4.2 kg which is about 9lbs pull. I recorded 7lb on the fish scale . This means all of those 7 lb rainbows were actually 9lb!

Either way the clutch is easy peasy and I haven't fussed with it in years.

Glen

 
I've had Venhill nylon coated clutch cables and I don't know if I put too sharp a bend in it, but the cable partially cut right through the nylon and jammed the cable making it hard to use. This happened a couple of times, forcing me to renew the cable.


Venhill Featherlight aren't nylon lined, perhaps you had some other brand.
I had nylon line throttle cables on the OZ Vincent. After two days of riding in heavy rain on our annual trip to California the throttle began sticking. Nylon is hygroscopic so it tends to swell up when wet.
The Venhills Featherlight use a Teflon lining. I installed all Venhills cables on that bike about ten years ago, no issues with rain riding since making the change.

Glen
 
Gents,
I have read as much as I can on this issue but I'm not sure on a few things.
1977 Mk111 that was rebuilt at 12 k miles.

At this time I fitted a Barnett clutch which has steel plates with friction plates.
I've since travelled 14 k miles and lately the clutch as become noticeably heavier to operate (could be I'm just getting weaker with age) and doesn't disengage completely. Seems to drag making neutral hard to find.

Cable is not at fault I'm pretty sure, and all adjustments seem ok.

I removed the clutch and washed in petrol as it did have a slight gear oil smell.
Checked the inner and outer clutch basket for wear, the inner has slight marks from the two middle fibre plate's teeth, the rest are ok. The two middle fibre plates teeth are slightly worn. But they slide over the centre driven cog easily.

All the steels are like new.

The clutch operating lever and the operating roller appear to be in good order.

After washing the plates in petrol I oiled them with engine oil and reinstalled the clutch and pressure plate, adjusted as per the manual.

I doubt it will slip, as it didn't before, and I think the dragging was dirty contaminated plates.

But it still seems hard to pull the lever. We measured it at 10kg and over at the lever.

Any advice re the heavy pull ????

Regards
Graeme

You need to adjust the thickness of the clutch plate stack. Do this by subbing 2 750 friction plates for 2 850 plates. The 750 plates are 3.5mm thick while the 850 plates are 3mm thick. You may need to go to 3 750 plates if your 850 plates are worn thinner. You should also clean the oil off the plates. This should get you a 2 finger clutch and not a 2 fisted one. Make sure your cable isn't worn or pinched.
 
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You need to adjust the thickness of the clutch plate stack. Do this by subbing 2 750 friction plates for 2 850 plates. The 750 plates are 3.5mm thick while the 850 plates are 3mm thick. You may need to go to 3 750 plates if your 850 plates are worn thinner. You should also clean the oil off the plates. This should get you a 2 finger clutch and not a 2 fisted one. Make sure your cable isn't worn or pinched.

850 owners who perhaps don't happen to have spare 750 friction plates lying around can fit a cheaper thicker plain plate (or plates) from RGM.

https://www.rgmnorton.co.uk/buy/commando-clutch-pressure-steel-adjuster-plate-3mm_3881.htm

https://www.rgmnorton.co.uk/buy/commando-clutch-pressure-steel-adjuster-plate-4mm_3882.htm

"STEEL COMMANDO CLUTCH PLATE 4MM THICK, ALLOWS THE CLUTCH PLATE STACK HEIGHT TO BE INCREASED AND SO LIGHTENING THE LEVER ACTION. (THE THICKER THE PLATE STACK THE LIGHTER THE LEVER ACTION). THE STANDARD PLATE 060746 IS 2MM THICK. 0607643 IS 3MM THICK."
 
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