Clutch advise

[evochris]

Hi all, I know it’s been asked loads of times about the clutch but can’t find by searching anything particular to my question, so I am hoping with the expert knowledge around here someone could guide me to solving my clutch anomaly. 350 F2 standard apart from reeds and Alonzo pipes, runs like a dream, except the clutch has something weird going on.

Fitted new EBC plates with new Yamaha standard springs, (tried with new EBC HD with same results) clutch case lever arrows line up as per manual and suggestion on here, new Yamaha clutch cable, clutch o rings removed, cable routed on the outside as best as possible for the coolest position, clutch basket free play seems minimal and ball bearing and pressure plate looks good. 100 miles covered since replacement.

So when cold I have 1/4” play in the lever, great, warm up and I get about an 1/2 + play, adjust to 1/4”, bike gets hotter after few 100m 1/2 on the temp gauge and a bit of traffic, get another 1/2” + play adjust to a quarter again, then seems to be stable. When cold again, the lever has no free play and is tight so I adjust all the way back to 1/4” play. It’s always been like it before I changed everything.
Has anyone else experienced this? What else do I need to look out for as would love to solve it…..

what do you reckon?



IMG_3831 by chris tring, on Flickr

[midlifecrisisrd]

Did you change the steels?

If slightly warped they may be distorting more as it heats up

Either way your clutch stack height is increasing as it gets hot

There is usually a bit of this but not as much as you have

I usually set the free play when it's hot

Steve

[evochris]

Hi Steve, yes forgot to mention, the originals had some slight discolouration in certain areas as if they were warped so replaced them. Did not buy genuine though….TRW…….should I? I have adjusted hot but it’s under tension on the cable now cold. Forgot to also mention I used light gear oil for the gearbox as recommended on here. I had standard oil as per Haynes manual before, again no different.

Any ideas what would make the stack increase in height with heat apart from warpage?

[JonW]

I assume you offset the steel plates as per the manual? you didnt say but...

I think you'll be down to replace parts and see whats different. I would try different steels and see if that was the issue.

I also assume the springs are new and tight? you havent got one or two bound up with a washer or something silly to allow some parts to get out of line when hot?

[headcoats]

Mine does it on my red LC with PV engine, that has after market plates and when cold it feels like no play at clutch lever but when hot the free play appears !
Clutch has never slipped and been like that over ten years,same clutch too

[evochris]

Hi fella’s thanks for the advice. Yes I put the plates staggered, I have had it apart a few times and did plates first, then steels and finally new Yammy springs with no difference at each step so thought there is something else going on here, I feel like I have eliminated the obvious stuff.

Would love to crack it though, all me other stuff doesn’t do it, and it would be nice to find it.

I don’t like stuff not right, I will gather some Yammy steels, a new basket bush, ball and pushrod for the next adventure in there.

[JonW]

Hmm... defo weird but keen to know what this is now, please do let us know how you go.

[evochris]

Hi Jon and all, so today went out to a local bike cafe with the rd, 30 degrees plus and it behaved perfectly, I adjusted it hot on Friday and it seems to be behaving, just a small amount of slack but nothing like what I have seen, do you think the clutch plates needed bedding in? I remember it doing it when the original clutch was in but I only ever adjusted the lever cold. So quite happy with it today, any changes I will let you know.

Thanks for all your ideas and assistance.

[muttsnuts]

when you fitted the new fibre plates did you pre-soak them for 24hrs before hand in the same oil you are using in the gearbox now ?

[JonW]

Sept 10, 2023 12:00:10 GMT 1 evochris said:

Hi Jon and all, so today went out to a local bike cafe with the rd, 30 degrees plus and it behaved perfectly, I adjusted it hot on Friday and it seems to be behaving, just a small amount of slack but nothing like what I have seen, do you think the clutch plates needed bedding in? I remember it doing it when the original clutch was in but I only ever adjusted the lever cold. So quite happy with it today, any changes I will let you know.

Thanks for all your ideas and assistance.

Everything wears in, not least wear components, but not like what you had going on.

Glad its getting better tho, does sound like youre fixing it somehow with the work

[Tobyjugs]

The same thing was happening with a friends Honda CB750.
I changed the frictions and renewed the oil and it was ok again.

[evochris]

Thanks guys, I will get out on it again Saturday for another try out, any excuse lol . At the moment I have the bike in bits hunting a small coolant leak, had the rad pressure tested with no faults, looks like it the return pipe to the expansion tank as the clip that hold the pipe is loose showing a little coolant splash around it, which in turn landed on the rad making me think i had a leak.....will be back together tonight once my SS jubilee clips arrive.