Were there any mods for lightening the clutch pull on these bikes? It's not awful but compared to my SWM it's heavy. I have a new cable and its routed properly.

I can see that a longer clutch arm will lesson the pull.

I did speak to a guy at a trial with the most original Cota 348 you are likly to see and he had removed two clutch springs. He told me he had no issues with slippage in top gears?

many thanks guys

I fitted and easy pull adapter on mine and it does reduce the pressure.  One other consideration for you is the kick start gearing is very high ...the shaft is almost unobtainable - you can reduce the stress and wear in this with a simple compression release.  Not sure about the 72 but mine has two spark fittings I use the top one for the decompressor.

Ahh, good point on the decompressor, I use one on my Speedy, best thing ever fitted to a trials bike in my opinion.

Kick start shaft....isn't it the later models...left hand chain run that are impossible to source or is it indeed all of them?

not sure about older models but I know my 76 model is not to be messed with ...I do have a spare shaft locked away in my safe

 

Make sure you have high leverage ratio hand levers. The standard AMAL levers they came with provide such a ratio. Many other common levers do not.

You can reduce the lift of the clutch release cam.

You can reduce the clutch pressure plate force.

A good way to judge when it has just enough force to not slip in top gear, without having to keep putting the cover back on again and test-riding, is the knowledge that if you can kick it over compression without the clutch slipping, there is enough force on the pressure plate that it wont slip in top gear when riding.

Edited May 20, 20179 yr by feetupfun
thought of something else

How are you relieving the clutch plate pressure?

Removing a spring at a time or different springs?

Cheers

Because the monty uses cross pins through holes, options are limited

Replace the springs with lower rate springs, or shorter springs, or a combination (you would need to work out your existing spring rate and preload and free length, and have access to the dimensions of other clutch springs to choose from)

Machine the pressure plate friction surface back a bit at a time. If the pressure plate is borderline stiffness already this would not be a good choice

Take out a driven and drive plate pair (this is very cheap and easy will probably be too much reduction in pressure plate force and also reduces the effective plate area so will probably slip)

If you have 6 springs you can usually take two out and try it. With 3, 4 or 5 spring clutches, this idea won't work well because the pressure plate will not stay straight when the clutch is disengaged. If you take 2 (opposing) springs out of a 6 spring pressure plate, there is a risk of the pressure plate flexing which means that the clamping force may not be evenly distributed which may cause uneven wear of the plates and pressure plate, and poor disengagement. I can't remember how stiff a montesa pressure plate is to make a recommendation on this, but I have done this mod to some of my TY250 motor trials bikes and it works great.

Shorten your springs a bit at a time by grinding and retesting. This requires care to maintain the end flat and perpendicular, and to keep all the springs the same length

My 348 has a completely standard clutch carefully set up, good cable routing, high quality cable, lever ratio (AMAL levers), lubricated cable, lubricated camshaft and cam and has a nice smooth action. I don't use it in sections though because I don't like the way it engages slowly, and the motor characteristics better suit riding with a dead throttle and not touching the clutch lever.

 

Cheers