more clutch questions

[AMCQ46]

Clutch on mine has been getting worse over the last year, but it is now so bad I have to do something.

so teh symptoms are:

1) the rpm threshold where the "grab / Screech" effect will happen has dropped to just over 3000rpm, so you cant try and blast into a roundabout from a standing start
2) the bite point is with the clutch lever almost fully out
3) when I am caning it hard, I can feel & hear it is slipping for a moment as the engine hits 7000rpm. happens with both clutched and clutchless up-shifts.

so got back from Devon and decided to pull it apart.

Steels all look good, no discolouration and normal wear markings
Friction plates are 3.8mm thick, which is close to std and well above teh 3.5 min.
one observation was that the plates close to the inside of the pack were dry, where as the outer ones were oily and wet. .. is that normal?
springs slightly shorter than new spec, but still well above min spec.
Pushrod is straight and has no corrosion or scratches
slave cyl has no scratches,
the fluid had been changed and is already black and perhaps level is lower than it was
basket has only the mildest polish marks rather than ridges where the tabs rattle

so this is not what I expected to see. I had imagined that the frictions would be too thin and there would be heat discolouration on teh steels ......

So I have a new set of friction plates on the way, but what am I missing?

[popkat]

The black fluid must be from inside the clutch line, if it's also dropping then there has to be a small leak somewhere, new seals in the slave or an Oberon replacement, if clutch line is stock change it. when you put the new plates in (hope you bought standard Honda ones) put some EBC springs in they are 10% stiffer




.

[fabiostar]

might not be your problem but one i had, the blue motor started to slip so i put new plates in,new springs atc and it was actually worse than before. it was a heavy duty kits from EBC just like the yellow bike had got without problem...

so i pulled it apart and inspected everything. all was good, back together and still slipping but i did notice the plates seemed a bit loose in the basket, as it stack height.

so apart again. this time, the two outer plates that sit in different tabs on the basket i changed them round so they sat in line with all the other plates, the stack height was then tight and its not slipped in the last 1k..

[AMCQ46]

The black fluid must be from inside the clutch line, if it's also dropping then there has to be a small leak somewhere, new seals in the slave or an Oberon replacement, if clutch line is stock change it. when you put the new plates in (hope you bought standard Honda ones) put some EBC springs in they are 10% stiffer




.

its an EBC HD friction kit not std honda, but I will also get some springs and a slave repair kit

[popkat]

Hopefully works then, heard too many times that EBC plates don't work and cause problems, I only ever fit genuine friction plates regardless of make of bike.



.

[MacV2]

Hopefully works then, heard too many times that EBC plates don't work and cause problems, I only ever fit genuine friction plates regardless of make of bike.

Shhhh Malc.. he hasn't paid for them yet & they are already in the post...

[popkat]

Hopefully works then, heard too many times that EBC plates don't work and cause problems, I only ever fit genuine friction plates regardless of make of bike.

Shhhh Malc.. he hasn't paid for them yet & they are already in the post...

sorry


.

[AMCQ46]

what is bothering me is that the clutch friction plates all measure up close to new spec, so wear is not the root cause of my 3 problems..... so although I will put the new plates in I don't see why it is going to help fix anything.

also can some one confirm which way the conical washer should be fitted [the one that is fitted before the first friction plate] .. currently it is tapered towards the engine, and the open side towards the outside.

[lloydie]

Might be worth replacing the dished spring plate mate

[lloydie]

https://www.lingshondaparts.com/honda_m ... ock_05=hmc
No.7&8

[KermitLeFrog]

https://www.lingshondaparts.com/honda_m ... ock_05=hmc
No.7&8

On my racing two strokes I used to drill oilways in the inner clutch hub (item 4). Usually about four 3mm holes in the valley of each spline. Not sure how much good it did; it was to cool the plates. Since you mention some of the plates are looking dry that may help.

It's a lot of holes but I never had any failures of the inner hub.

[AMCQ46]

there are some holes mid way down the spline which I assume is to feed oil in to the plates, but the dry ones were further inboard

[KermitLeFrog]

there are some holes mid way down the spline which I assume is to feed oil in to the plates, but the dry ones were further inboard

Drill some more further inboard.

[8541Hawk]

Well personally it sounds like the original issue was caused or could have been caused by air in the system.
It is very easy to get air trapped at the banjo fitting on the master cyl.

While it is a bit counter-intuitive the signs of air in the system is clutch slip under load.
Most would think that air would cause disengagement issues but that doesn't happen.
What does happen is that because it is so hot (the push rod is as hot as the rest of the engine internals, that is why the fluid turns black so fast) that the air expands and slightly pushes out the slave cyl.

With the hard parts checking out and in-spec all the signs point to an air bubble

[AMCQ46]

Well personally it sounds like the original issue was caused or could have been caused by air in the system.
It is very easy to get air trapped at the banjo fitting on the master cyl.

While it is a bit counter-intuitive the signs of air in the system is clutch slip under load.
Most would think that air would cause disengagement issues but that doesn't happen.
What does happen is that because it is so hot (the push rod is as hot as the rest of the engine internals, that is why the fluid turns black so fast) that the air expands and slightly pushes out the slave cyl.

With the hard parts checking out and in-spec all the signs point to an air bubble

i will have a look at that too, thanks Hawk