250ES Clutch slipping

[Airmapper]

During my recent refresh on the 85' 250ES, I went in to fix the timing chain, so all the clutch stuff came out and I reassembled. Now I have it running again, I have found that the clutch is slipping. I probably did something wrong.

It shifts fine. It slips in forward gears only, seems nice and stout in reverse, although I didn't test it other than seeing if I could hold it back like I could in forward. It will actually pull itself along on flat ground, just not up any grade at all with me on it. (Put your feet down and you can stop it while giving it gas.)

New oil was put in, Honda GN4 10W-40 4-Stroke Motorcycle Oil. I'm thinking that is fine for this application, as I bought it as part of a kit for Honda ATV's with a new filter and such.

I did replace the one way bearing, I confirmed it is in correctly, as the kick start works now whereas it did not prior.

I also re-checked the clutch adjustment. Turned the screw all the way out, 1/4 turn back in, then locked it with the nut. It shifts fine, a bit firmer now with the readjustment.

I think the centrifugal clutches are almost new. I replaced those a while back but it has sat a while since then. Since it pulls in reverse, I don't think that is my issue.

The disk clutches looked okay, probably wouldn't hurt to replace them though and I will since I'm going back in there. (Suggestions on good disk brands welcome) But, I don't think that is my issue or I would have noticed it before I parked it several years ago, and again, it pulls in reverse.

I think I may have incorrectly assembled the disk clutch packs with the springs. I read over the service manual extensively, but I'm not quite sure what went wrong.

Any ideas given the above symptoms? Thanks. :)

[tri again]

clutch adjust q? all the way out and then 1/4 turn in?
not sure if that's right.
May be reverse thread, so screw in till it touches, than out 1/4 turn for freeplay?

wouldn't that be nice if that was it?

I too, get tunnel vision when I work on my own stuff but great at giving advice.
Hope it's right.

[Airmapper]

I was hoping you had it pegged, but unfortunately it appears I did the adjustment correctly at least.

Service manual says "counterclockwise" until resistance felt, then "clockwise" 1/4 turn, and those are the directions I used.

[tri again]

I was hoping you had it pegged, but unfortunately it appears I did the adjustment correctly at least.

Service manual says "counterclockwise" until resistance felt, then "clockwise" 1/4 turn, and those are the directions I used.

Yeah, I thought something was backwards, as if reverse screw for adjusting
but sounds like you got it right.

so no one put in any antifriction additives trying to help?
There are tons of pages on oil but thinking back in the 80's,
all we really had was regular 10-40. types and straight weight
The newer oils have reduced zinc to prevent converter contamination and
is harder on flat tappet cams but that's all I've heard.
You honda oil has to be better than what most of us use unless it's really specific for
some oddball application.
Thinking if it says 'for wet clutch' almost has to be ok.

What did the old oil look like? normal dirty or 'fuzzy' from clutch material?

It's been so long since I've been in a clutch, I'm afraid to give wrong info.
but maybe this post will spike some new comments.

Someone will chime in with good and bad clutch suppliers.
The only thing that sticks out is that they want to be soaked in oil before assembly.

Sure hope it goes easy for you.

[Flyingw]

EBC clutch disks is what I would recommmend. The slipping is worn out rotating clutch disks. Since you're going to have the clutch torn apart, be sure to put fresh fiber and steel plates in and be done with it for a while. Be sure to turn the clutch adj screw CW a few turns before installing the clutch cover then readjust after the cover is installed.

[Airmapper]

so no one put in any antifriction additives trying to help?

No additives, just the straight Honda oil. It did mention for clutch use on the labeling. My Big Red did sit for several years unused with old oil in it. I'm guessing that may have had a detrimental effect on the disks, as they were worn pretty good already.


What did the old oil look like? normal dirty or 'fuzzy' from clutch material?

I've slept since I drained it, but I think it was just normal dirty, smooth consistency but all grey.


EBC clutch disks is what I would recommmend. The slipping is worn out rotating clutch disks. Since you're going to have the clutch torn apart, be sure to put fresh fiber and steel plates in and be done with it for a while. Be sure to turn the clutch adj screw CW a few turns before installing the clutch cover then readjust after the cover is installed.

Thanks, will do. I went ahead and ordered fiber disks yesterday, and EBC is what I got. I also just ordered the metal plates, didn't think about getting those.



I'm guessing the reason it pulls better in reverse is they are directionally worn, and since reverse is not used as much they do have some friction remaining in that direction?

Is there anywhere I can go wrong tightening things (like the springs) down that might be unintuitive? As in, are the clutch plates supposed to be tight or loose when I'm done assembling the pack?

[oscarmayer]

yea order a new clutch disk set. you will need the side cover gasket too. but should not take you too long. also make sure you get the clutch removal tool or you will not get the nut off. LKOL I said nut off ;-) ( hotdog went there)

[Airmapper]

you will need the side cover gasket too. but should not take you too long.

I've already been in there once, I got a gasket and it was junk. Is it the same gasket for 85-87? I find a few listing all 3 years. I can't find a quality gasket for 85 alone, but for 86-87 I find better ones listed. The one I got was like shredded paper cardboard junk, didn't fit all that well. I had to tack it to one side using some of that gasket sealer sticky stuff. I'm waiting to see if it comes off in one piece, I know it's not recommended to re-use them, but it's only been on there a month. If I can't re-use it, I need a better one.

I'm leaking oil, but I think it's just the reverse shaft seal. I have a new one to go back, and I'm hoping that is my leak.


also make sure you get the clutch removal tool

Oh yeah, I got one of those, works like a charm..... :naughty:
https://lh4.googleusercontent.com/GNeyUMBZAFQemDVVkxadlJm4T8qvqs0tYpAmhtFGk5M=w1137-h853-no

[oscarmayer]

I believe 85-87 is the same gasket if it is the clutch side. so should be ok.

[Airmapper]

Well I finally got all the parts in, found time to install, then had to figure out why it wouldn't start...anyway today is the first time I've actually rode my Big Red in a very long time.

Clutch works now but is still slipping even with all new internals. 1st holds good, but if I push it in 2nd or higher it starts to slip....

[Dave8338]

Did you pre-soak the fibers prior to install?

[Airmapper]

Did you pre-soak the fibers prior to install?

Yes. For a few hours. They sat for almost a week after install as well, after being soaked in oil.

[Dave8338]

One other thought, did you measure the springs to see if they were within spec?

[Flyingw]

The centrifugal clutch shoes may be worn beyond limits or your clutch adjuster may be set too tight. Not letting the clutch to engage completely.

[El Camexican]

Why do you "soak" your clutch plates?

[86125m]

I want to know why you would soak the clutch plates as well i've never had to soak the clutch plates.

[Flyingw]

Wet plates should be wet with oil when you assemble the clutch. There is no need to long soak them just as long as they are wet when you put it together. I usually put some oil in a paper plate. Dip the plate one at a time on both sides then put it in to the clutch basket. The book usually says something to the effect of "Coat the clutch disks with engine oil". This is to ensure the clutch disks are lubricated prior to the first engine start after replacing the clutch pack. Failure to do so could result in warping the clutch disks.

Ref: SX manual page 8-18 in the note block as one example

[El Camexican]

Wet plates should be wet with oil when you assemble the clutch. There is no need to long soak them just as long as they are wet when you put it together. I usually put some oil in a paper plate. Dip the plate one at a time on both sides then put it in to the clutch basket. The book usually says something to the effect of "Coat the clutch disks with engine oil". This is to ensure the clutch disks are lubricated prior to the first engine start after replacing the clutch pack. Failure to do so could result in warping the clutch disks.

Ref: SX manual page 8-18 in the note block as one example


Exactly, The plates don't absorb any oil at all. If they did then they would also crumble apart after a few minutes of use. a light coating of oil keeps the steels from rusting if the engine is left to sit after the build and keeps it from sticking the first time you put it into gear.

[Airmapper]

Thanks everyone.


One other thought, did you measure the springs to see if they were within spec?

I did not. I should have. I will if I pull the cover again.


The centrifugal clutch shoes may be worn beyond limits or your clutch adjuster may be set too tight. Not letting the clutch to engage completely.

Centrifugal clutch isn't worn, it's practically new, but it's aged, and sat for several years.

Clutch adjuster too tight, meaning it shifts loose or firm? I re-set it after the new plates were in, but I did notice it shifts very firm, as in the pedal is stiff. It does have a bit of play like it's supposed to, but you have to pull on it pretty firm. I had boots on during my shake down ride and had a hard time shifting, which when I rode it years ago it was very light and I could shift a lot smoother.