Clutch Slipping?

Thanks to Len for parts and this forum for instruction and advice, I have my '82 Seca running quite well after 15 years in the corner of the garage. Pics soon!

What I do have is a clutch that is not smooth and feels like it is slipping. I've lubed the cable and adjusted the lever but I think it's the clutch itself. It feels like it slips after shifting.

I find no evidence of any binding of the cable and have lubed it with no change. Could the clutch be slipping and is there anything I can to to clean or free it up for smooth operation?

 

If the Cable is Slacked and the Clutch is Slipping here are some reasons Clutches Slip.

Time for a New Clutch job.
Wrong Oil. Engine Oil with "Friction Reducers"

 

What sort of oil do you use?

 

i'm having similar issue. Clutch started slipping a bit.... only when I shift up, hard on throttle, and drop the clutch. takes a few seconds to bring the rpm back down. I rarely do that.... Then I did an oil change and it got sunny for a few days so um..... yea things got worse...... Castrol 20w50 4stroke dino stuff.


I think i'mma need a new clutch...... unless this is normal......? My first bike. First wet clutch anything. So no clue how they're meant to work.

 

What grade was it? anything "better" than SG will have friction modifiers incompatible with our drivetrain & starter clutches...

Same for the O/P, what oil?

The clutch shouldn't slip under any conditions (apart from pulling the lever when you want it to! lol) so something's not quite right in both cases. Also worth noting, if the wrong oil has been used it can take time & couple of extra oil changes for things to settle down again.

 

Fitz's Write-up is great - the clutch is super simple to do -

http://xjbikes.com/Forums/viewtopic/t=29541.html

- no need to drain the oil if you put the bike on the side stand

- I scraped the old gasket material off both the cover and mating surface, and then used a bead of black RTV sealant to seal it back up, and it's never leaked.

- New bolts are a nice peace of mind thing, check your local yammie dealer, they were only 1.75 each at mine which is where i got em from.

- your plain plates are more than likely okay, you'll be able to tell when you pull it apart. Just clean them up with green scotchbrite pads just cause.

- Soak your new friction pates in clean oil before installing, i just threw them in a bowl when i started the process.

- USE A TORQUE WRENCH. On both the spring bolts and the cover bolts. Snapping off a spring bolt happens way more than it ought to and then you'll be shopping for a new basket. bad day.

I got the EBC cork friction disc kit and EBC springs, and am more than satisfied. Has a whole new bite now

Powersports superstore has killer prices:

http://www.powersportsuperstore.com/EBC ... 092727.htm

http://www.powersportsuperstore.com/EBC ... 104837.htm


EDIT: This is all cobsidering you're using a conventional oil without friction modifiers - I have always used Castrol 4t 20w-50 with satisfactory results - economical and widely availible:

 

I've had clutchs slip that measured brand new but the springs were a little short.
Measure your springs

 

Yup I'm using Dino oil just like the one in the pic. Its the only castrol Dino in town so if this ain't gonna work then nothing is.

My clutch is engaging very late. As in I don't have to pull the lever very far to rev freely. And the cable is adjusted and lubed properly.

I don't know about this case, but in a car that'd mean the friction material is thin.....
Also the lever is rather heavy.... Not sure if previous owner put some aftermarket springs in or something. So I'm not so sure if springs are the problem.

What's the measurement anyways?

 

this is a goodin lol I have an 85 Maxim 700 that sat for ever. Got it going and a few miles on it and noticed that when I put the bike in gear it is smooth to shift. When I release the clutch it is "tight" as in the lever is maby 3/4 inch to inch off grip is this right? Personaly I would like to have more play in the clutch the cable is tight at the case and holds tention on the lever there . I am running yamaha 10w-40 oil with a ounce and half sea foam in it to help clean up interanals of motor.

 

from what i read, our clutch doesn't like seafoam...... i could be wrong

 

Hummmm not good lol glad I only have a few miles on it with that in there anybody know for sure?

 

Good point on the oil, my Beemers have dry clutches and I forget that the type of oil will have an effect on clutch operation with these bikes. When doing the resurrection I changed the old oil and filter just using some car oil I had on the shelf. Back in the day I always used Bel-Ray oil products but haven't seen any on the shelves in quite some time. I have to order Golden Spectro 4 for my airhead Beemers so I may have to order the Seca's oil as well.

I doubt the clutch is worn, its only got 18.5K on the odo.

Thanks

 

I ran Seafoam in the oil for 500 miles to help free up a suspected sticky ring (which unstuck nicely ) without any hint of clutch slippage.

 

Ok sweet I only ran it for 60 or so easy miles so far would like to run it for a hundred to try to clean it up a bit seems solid any thoughts on clutch adjustment ?

 

But if you're fitting a new clutch, why not drain the oil and fill with fresh anyway, always give a new clutch fresh oil :wink:

The specs are all in the manual, you really need one they're brilliant

spring free length for 750 is 41.2mm (service limit 40.2mm).
Plain plate thickness 1.6mm, max warpage 0.05mm.
Friction plate spec 3.0mm (service limit 2.8mm)

No it ain't right. Could be a badly adjusted, or more likely knackered, cable if it's not returning properly after you pull the lever.

 

Let's go back and discuss why a 30-year old clutch needs to be rebuilt, regardless of how thick the friction plates measure.

Do you remember/know what linoleum is? What it truly is? It's dried OIL.

Now then. Our clutch friction plates are a collection of tiny brake pads glued to a metal plate. These are made of a friction material that's made to "live" in motor oil. Nice clean, motor oil. BUT they're not submerged in it; they get continually dipped in oil.

Until the bike sits. For years. ALL of our bikes have sat at some point; or they'd have a gazillion miles on them.

If the bike sat on the centerstand, half of the clutch was sitting dipped in the "storage" oil, whatever that may have been;

if the bike sat on the sidestand, the clutch was not in the oil at all.

So what happened to those tiny, oil soaked friction pads? The ones that weren't sitting in oil DRIED OUT and became... little linoleum pads.

Even though they may not be WORN, they no longer have their original gripping properties; and once they get called upon to be clutch plates again, they quickly glaze and quit working so well, and/or begin to crumble, etc.

Plus, they've left an "imprint" of themselves on the plain plates, which contributes to them having difficulty gripping as they should.

The moral of the story is that you haven't completely recommissioned a quarter-century old bike until you've refurbished the clutch. Usually all that's needed will be friction plates and new pressure plate bolts and springs. (The springs sag and the original bolts will want to break.) But you'll have to do it sooner or later; don't expect an original clutch to perform properly.

 

First off Thank you RickCoMatic for the easy way to adjust the clutch lol never thought that as a measuring tool lol. I do plan on getting some miles on my bike and kinda figured on replacing the clutch this next winter. I hope it will work for the summer I do put alot of miles on last year my bikes seen over 12000 mi. We will see tho, in the event of needing a replacement clutch is there an upgraded one out there? I will be riding 2 up on this one alot and in hills on occation.

 

Thanks Fitz, it's now on my list of things to do.

 

how accurate would you say those plastic calipers are? I'm guessing they'd still be much better than measuring tape.......... I havn't had to use calipers before so I don't think it'd be worthwhile to invest in an expensive pair.......

 

forgot to mention, i'm thinking of measuring everything out before i start replacing

 

If bigfitz52's statement is true.....

Then does that mean if I pull everything appart, and everything measures out to be in spec, then i technically could soak it all in say... sea foam, for a day or so, and wash it out with brake clean or degreaser, then use scotch brite to rough up the surfaces to give it a clean new bite, and soak them all in fresh oil and reassemble......
That might do the trick?

But I bet my clutch is toast. I'd be genuinely surprised if the friction plates are in spec.



And how heavy are the clutch levers supposed to be?!?! I have to clue if the PO put in aftermarket springs or something, because it wasn't slipping untill the past few weeks, and because the lever is annoyingly stiff......

 

Not very. Get yourself an inexpensive set of digital calipers. Digital Calipers on Amazon For the princely sum of $20 (including shipping) you can buy a level of accuracy that cost somewhere on the high side of $100 when your bike was new, and you don't have to learn how to read a dial.

 

I already know how to read the classic stuff. Went to school for auto tech, it was mandatory.

Should I be worried shipping would damage the digital ones? I was told one drop and they're no longer accurate....

 

My dial caliper came in a padded case, that was in three layers of bubble wrap, that was cushioned by four air bladders. It should be fine. I think the digital caliper would be more able to deal with a short fall than a dial caliper since there are fewer moving parts.

 

i have about three (so i can find 1) of those 20$ calipers from harbor freight, their pretty much bomb proof

 

Another thing with the digital ones, if you do drop them and tweak the jaws, it makes no odds so long as you zero the display with the jaws together (done automatically at switch on)

 

-My statement is true; I have two roadworthy XJs and another on the way and I don't make stuff up.

-NO. They're truly linoleum now, no amount of flushing, soaking or degreasing will bring them back from the dead. Use Scotchbrite to clean up the plain plates; replace the friction plates (and springs and bolts.)

-Your clutch, if original, IS toast. Keep trying to ride on it and you'll just burn your plain plates and end up needing to replace those too.

-The stiffness is probably due to a worn-out cable that is rusted internally or has "popped" a couple of strands somewhere along its length; I would replace it too.

 

I replaced the cable just about 5 months ago and it's always been this stiff. Cable is working smoothly and everything.

It's an aftermarket cable but i don't see how that would make much of a difference if it's working smoothly.....

 

Word of advice to EVERYONE who plans on doing the clutch.
DO NOT RE-USE the spring bolts.

I took mine apart to measure up the specs (to my surprise everything was good except for plain plates.... guessing PO replaced friction plates and springs).

When I was reinstalling, I thought I just need to make a trip to the parts store tomorrow then it's coming apart again for new plain plates so I'll reuse the bolts for now.

I started torquing her and was a little worried as my torque wrench wasn't clicking when I was expecting her to. So I though, maybe my torque wrench is having a bad day so grabbed my ratchet and went at it by hand. I've been working on cars for 7 years now and know what a 10mm bolt should feel like and also snapped enough bolts to know how they feel that 1/8th of a turn before it snaps. Sure enough I turned the bolt just a bit and felt it wanting to snap. I gently backed the bolts out and you can SEE a section of the bolt has stretched and was just about to snap!

Some people say you can reuse them once or twice as long as you're careful and use a torque wrench.

Don't. Just don't. Don't even THINK about it.

 

What is peace of mind worth? If we don't mess around with questionable brakes, why skimp on the parts that might strand you 20 miles (or more) from home? Or cause much consternation and cursing? For a little over $160, you can get an upgraded kevlar clutch kit (friction plates, plain plates, and springs, get bolts elsewhere) from Barnett and replace EVERYTHING at once. No checking of specs or measuring anything. Replace the whole thing, get a new cable, install a new gasket, and don't cut any corners.

Put off the cosmetics and fix what matters. Then ride with the confidence that you've done it right.

 

You can also do a perfectly functional rebuild for about half that.

If the plain plates, hub and basket are in good shape, then all that will be required are new friction plates, springs, bolts and a new gasket.

Aftermarket friction plates (K&L or EBC) are fine, and actually a little better than the OE Yamaha parts; personally I prefer the feel of the stock springs.

You did LUBE the new clutch cable, right? Even brand new cables should be lubed.

 

K I just called a yamaha dealer to see if they have anything in stock and what their prices are....

Parts guy told me that it doesn't matter if my drive plates are .1mm-.2mm thiner than spec of 1.6mm, they won't be causing any slippage unless they are warped.

For some reason my a few of my drive plates are showing copper..... wtf?

I also told him my friction plates are all 2.92-2.98, which is in spec. But he said that most of the slipping clutches he's worked on are in spec but simply glazed and roughing them up will not help much.....

Is he just trying to sell me everything? I wanted to replace only the drive plates because that's what's out of spec, but at the end of the day all I care about is that my clutch stops slipping and be reliable with minimal cost. I wish I have the money to just replace EVERYTHING, and in that case I wish I had the money to buy a 2010 cbr1000rr Repsol edition.

 

mine slipping if you slam the throttle hard, just thought i throw out the amzon.com option, clutch plates and springs for $50, shipped (2-day shipping if you have amazon prime)

http://www.amazon.com/gp/product/B006B2 ... PDKIKX0DER

http://www.amazon.com/automotive/dp/B001IUJNCC


i think only my srpings are shot, but if i'm going in, might as well throw new plates in for the price.

 

It's really easy to pull everything appart to check. turns out my springs and clutch plates were all near new condition. the plain plates were warped way out of spec

 

I don't think those Springs for sale on Amazon fit our Bikes.

 

http://www.powersportsuperstore.com/EBC ... 057960.htm

"1980-1983 Yamaha XJ650 Maxim"

thanks for the concern, but amazon and powersportsuperstore say they are compatible, unless theres something i don't know?