Huntmaster Clutch Woes

[graham.tiller]

Hi all - first time post, so please be gentle!!!

I have had a 1958 Huntmaster for the last seven years, and have never been happy with the clutch action.
Bite has always been on the edge of the lever pull, and it is either on or off (not at all progressive)

As we are laid up during the chilly season, i have used this as an opportunity to strip down and replace a few bits.
So new plates (three friction, four plain) pushrod and ball were ordered from Draganfly and fitted.

Late Huntmaster (with the GB box) is the one with the extra friction plates in the basket, and i can confirm it is the correct one fitted.
The dimensions of the centre matches, according to one of the other posts we found on this forum.

Double checked the length of Pushrod, which is 9 13/16"

We made sure that all the plates slide freely in the basket (licking the edges with a file to ensure there are no burrs)

Upon reassembly, we are still getting pretty much the same action.

Some of 'the boys' mentioned that I should just remove one of the plates, but this doesn't work at all, as there is too much slack, even when the springs on the pressure plate are graunched up.

I am out of ideas, and have tried adjusting everything (cable side on gearbox adjuster and lever as well as gearbox side on the operating arm)

Any hints, tips or devine intervention would be greatfully recieved at this point... I ride with others that have 250 - 500cc singles, and need my clutch to keep me back!!!!

Thanks in advance,

Graham

[Steven.Carter]

Welcome to the forum Graham. Have a look and see if the clutch baskets spin true, if they are not assembled correctly they can appear to spin like a buckled wheel and that will give you the symptoms that you are experiencing.

Steve.

[adrie.degraaff]

If the clutch housing is not worn try the vulcanised plates, they are sliding more than cork.

[Simon.Gardiner]

Graham:

With the clutch cover off and in neutral, pull the clutch in while prodding with the kickstart and check to see if the pressure-plate is freeing off evenly. It does need a bit of an 'eye' but if you can line up the edge of the pressure plate on something you can get an idea if it's spinning 'true' or not.

I find the instructions about tightening the springs so that they're all level doesn't usually work well enough and I usually have to adjust them individually to get the plate to pull off evenly.

[brenton.roy]

Hello Graham, welcome to our group.
You seem to have tried a lot of the logical things. Steven / Simon's advice about adjustment should be first.
If this doesn't work, I have a couple of questions.
Does the clutch lever feel heavy to pull? (relative to other period bikes)
Does the bike "grate" into first, and other gears? and will the bike sit at the lights in first?
Have you checked the condition of the clutch needle roller bearing - (grease and damage to the cage / rollers)?
Does the clutch pushrod show evidence of blueing (getting hot)?
regards, Brenton

[keith.hodgenia]

Hi Graham, sorry if I am stating the obvious but it pays to check. Are you adjusting cable and operating lever in the right order. In general you should back off the cable adjuster first then adjust the operating lever (gearbox end) till there is a small amount of free play then adjust the cable till it has a bit of free play as well. There will be an optimum angle for the operating lever (gearbox end) as I don't have a Huntmaster I leave that for others with more experience. Keith.

[Steven.Carter]

The Huntmaster is the same as all the rest of the bikes with gb boxes Keith. The way you recommend in setting up the cables is the way I do it. I did once have a bike with a very stiff clutch, fixed with a freshly oiled cable and I got the leaver in the gearbox at the wrong angle. The leaver was leaning back towards the outer cover which means the cable had to pull the thing from an awkward angle. Strewth did that make sence Its so hard to get this stuff into words.

[keith.mettam]

Graham,
If you've checked as per suggested and cable is routed for smoothest practical route, is the pushrod ball bearing there or missing ? Only other thing I can think of for a fierce clutch might be end play in the gearbox mainshaft. Have you checked this out yet ?
Good luck with it.
Keith.

[graham.tiller]

thanks Gents - certainly some things I can check on...

Steve, luckily on the later box, the lever is all inside, so i think it can only go on one way?
Do you mean the basket or the pressure plate in terms of concentricity?
On mine, there is a very slight wobble from left to right (around a 2mm deflection) which seemed to be in one place as opposed to building up over the cirumference of the basket.
There is no up/down wobble that we can see.

We don't think that clutch cable routing is an issue at this stage, as the tank is off the bike, and currently the cable is sat where it wants to be, so I think we should be able to discount that one.
The cable itself is well made, with a nice thick outer, which stops you from making sharp turns with it anyway.

There are two adjusters on the cable, one on the lever side and a second in to the back of the gearbox.

The clutch lever pull is indeed a little heavy. However, i will be swapping to the 7/8" between pivot centres lever blade in the near future (once I find a nice quality set)

There is no real problem with sitting in first at lights, other than the all or nothing when I pull away.
Certainly no graunch or resistance getting it into first.

We have a new pushrod, and the ends are slightly blued (from where they have been heat treated)
However, the old pushrod wasn't burnt at all.

The ball bearing is new, and in place (correct dimension as per GB 52-58 box)

thanks again,

Graham

[pete.collings]

Are the springs all the same strength, either differing free lengths or weakened spring strength? I have fitted Triumph clutch springs in the past to lessen clutch slip, they work well but are a bit heavy compared to the Ariel ones.
A weak spring (or springs) could allow the end plate to angle a bit as the end plate moves back, even if it spun true on full extension.