Dragging clutch

[Scottvincent]

Hi Phil

No, it’s just a smear of grease that I used to hold the gasket in place whilst I did a trial fitting of the clutch.

Thanks

[K2-K6]

I can't quite see the angle of the arm from that view. 

Presumably you've adjusted as you described, touch screw in then back out a prescribed amount?

You can,  for investigative purposes, just touch the screw down and not go back to give slack to assess it like that. It may be a route to run as such initially to bed the assembly in and then reassessment after a few miles. That would give the most lift possible with the components you've got.

On these,  the clutch if you give it some hard launches to heat it up (no suggestion to do this, but illustrative) results in the clutch pack expanding and moving away from the lifter mech,  so it doesn't promote slip but more that you can't release it fully.  It's low risk to run it as suggested above as it won't ordinarily give a problem.

Worthwhile to try it and see what you get in respect of it dragging.

[Scottvincent]

Hi Jedi

I adjusted the clutch as you suggested and went for an exploratory ride. The bike went into gear without a crunch but was wanting to be off by itself. It could be held on the brake. Within 2 yards the clutch was slipping so badly that no further progress was possible. Ignominious return to the garage! I reset the clutch, as per manual and tried again. The bike went into gear without a crunch, but again wanted to proceed with or without me. This time the clutch engaged and rode as I would expect it to. Gear changes were quiet, even into first gear, but I could not engage neutral when stationary. The bike would stall when held on the brake.

I think that it needs a good long ride with frequent use of clutch and gears.

Any thoughts anyone?

Thank you

[Scottvincent]

Photograph of the angle of the clutch lifting mechanism

[Nurse Julie]

Try going back to mineral or semi synthetic oil as if I remember correctly you are using GTX

[JezzaPeach]

I may be on the wrong tack as I’m visualising the 500/4 mechanism, but could it have the subtly wrong model of or worn lifting cam/lever bit/ball bearings?

[Scottvincent]

Nurse Julie, I will give a mineral oil a try. I am supposing that back in the 70s, this is what Honda would have used? Any recommendations?

Thank you.

[McCabe-Thiele (Ted)]

Nurse Julie, I will give a mineral oil a try. I am supposing that back in the 70s, this is what Honda would have used? Any recommendations?

Thank you.

I've read lots of advice about Synthetics & Semis not being suitable for older bikes - Exol do a semi synthetic suitable for wet clutches. I'm going to probably use the Asda Mineral Oil.

[K2-K6]

Something odd with the clutch pack, and possibly it's "willingness" to sit flat when you assemble.

By tightening and not backing out the screw you effectively set the lift mech to touching the thrust bearing with no space, when you tried to use it the plates must have compacted more to then slip with it set like that. It moves the whole combined clutch plate pack toward the lift mech, which shouldn't happen.

Using it as you've set it now (after the pack has found a natural home point) will probably help and certainly allow you to asses it further. Gear changing won't change anything as such but clutch use to pull away etc will.

To make a problem statement,  the clutch mech lift is insufficient to make each plate run clear enough from it's neighbouring plates to prevent torque driving through them.
Ordinarily, a prime cause of that would be having bent or bowed plates. Are you certain that the plates are substantially flat (check on a piece of glass, for wave form and also for peripheral to internal diameter (making sure they are not cone shaped)  as any significant variance will take up space that can't be accessed by the lifter mechanism, and drive will always be in place as you have in dragging.

You can check them with feeler guages against a known flat surface.

[philward]

I had a similar issue on my ZZR1100 but not as pronounced as your issue. I changed the steel plates and that cured it. I would check the steel plates (as K2 - K6 suggests) before just changing them though as they are expensive - and may not cure the problem.

[Scottvincent]

Hi
I’ve checked the plates for flatness, all seemed ok. I am happy that the clutch lifting mechanism is working fine, the problem seems to be in the separation of the plates. Looking back I think that I can see what may have happened.
I believe that the F1 sat for many years after money had been spent on renewing numerous parts, I would imagine that the p.o. ran out of energy (or money). It was then traded in as an unfinished project to a local bike dealer in Norfolk who wanted to move it on quickly - this is where I came in as there is nothing I like more that an orphaned bike ( I have more in my shed)
I got it up and running but never touched the clutch. The bike had no oil in the tank when I got it and a stripped sump plug and I would imagine that the clutch was dried out. I assumed that new plates and springs would sort matters out, but thinking back, I don’t think that I soaked the new plates in oil and so just duplicated the problem. Things were definitely better after I soaked the clutch for a couple of days recently. Unfortunately I just changed the oil for fully synthetic, compounding the problem.

I will clean the plates and change the oil for mineral. Hopefully this will resolve the problem.

Thank you to everyone who contributed to the (hopeful) resolution of the problem.

[JezzaPeach]

Good job. Your case a useful learning curve for me as I nearly ruined mine by letting a leak cause the oil to get too low and had a similar issue.

[philward]

Hi
I’ve checked the plates for flatness, all seemed ok. I am happy that the clutch lifting mechanism is working fine, the problem seems to be in the separation of the plates. Looking back I think that I can see what may have happened.
I believe that the F1 sat for many years after money had been spent on renewing numerous parts, I would imagine that the p.o. ran out of energy (or money). It was then traded in as an unfinished project to a local bike dealer in Norfolk who wanted to move it on quickly - this is where I came in as there is nothing I like more that an orphaned bike ( I have more in my shed)
I got it up and running but never touched the clutch. The bike had no oil in the tank when I got it and a stripped sump plug and I would imagine that the clutch was dried out. I assumed that new plates and springs would sort matters out, but thinking back, I don’t think that I soaked the new plates in oil and so just duplicated the problem. Things were definitely better after I soaked the clutch for a couple of days recently. Unfortunately I just changed the oil for fully synthetic, compounding the problem.

I will clean the plates and change the oil for mineral. Hopefully this will resolve the problem.

Thank you to everyone who contributed to the (hopeful) resolution of the problem.

I hope you are right Scott but I have built 3 x 750's in recent years, changing the plates on all 3 and have never pre soaked the friction plates (just smeared with oil) - hope you sort it!

[Scottvincent]

Now you tell me!!

However, I’m not just basing my optimism on chance but on the fact that after I soaked the plates, the clutch felt considerably better than before. Hopefully the change to mineral oil will also incrementally improve matters. I am looking for for all the small detail adjustments that will add up to a larger improvement, as I cannot see anything fundamentally wrong with the clutch.

Thanks for the advice.

[K2-K6]

I'm not sure if I've followed the logic correctly on this one.

The general claim is that "synthetic" engine oil is considered (not by me) to make wet clutches MORE likely to slip. Ergo,  it follows that "mineral" engine oil will provide MORE grip from the plates,  which is the problem you are attempting to avoid.

It seems counterintuitive in logic terms.