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Clutch?

Started by Tapartacus, August 16, 2020, 03:12:17 PM

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Tapartacus

Hi everyone. It's been a while since I posted. Hope everyone is finding their peace in these strange times. I have a quick question about the clutch in my 92. It doesn't slip but it is difficult to put in gear. Can I assume the clutch is toast? The bike has 25 thousand miles on it which seems a bit early to have to replace the clutch. I also replaced the master cylinder with an FJR 14 mm one about 10 thousand miles ago. When I originally found I was having trouble putting the bike in gear I realized the fluid was low and topped it up. Unfortunately that didn't help.
92  FJ1200
89  FJ1200

red

Quote from: Tapartacus on August 16, 2020, 03:12:17 PMHi everyone.  I have a quick question about the clutch in my 92. It doesn't slip but it is difficult to put in gear. Can I assume the clutch is toast?
Tapartacus,

There is a brass bushing in the clutch lever that pushes the Rod, Push (Index #3 on this fiche) into the clutch master cylinder.  If that piece is worn or deformed, the clutch will act as you describe.  There may be nothing wrong with the clutch, but that bushing may be toast.  See Index #4:

https://www.partsfish.com/oemparts/a/yam/50043252f8700209bc78b255/front-master-cylinder-2

RPM has them; no need to buy a full rebuild kit to get one small bushing.  Lube that brass part, on a regular basis.  Also, check if there is any excess play in the clutch lever pivot.  

The Part Numbers for the FJR1300 and the FJ1100 are the same for Index #4.
.
Cheers,
Red

P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.

Tapartacus

 My master cylinder is that of a 2013 FJR
92  FJ1200
89  FJ1200

red

Quote from: Tapartacus on August 16, 2020, 04:02:06 PMMy master cylinder is that of a 2013 FJR
Tapartacus,

I just checked, the Part Numbers for Index #4 are the same for both bikes.

http://rpmracingca.com/proddetail.asp?prod=M%2FC%3AClutchLeverPivot
.
Cheers,
Red

P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.

Tapartacus

Great I'll have a look thank you.
92  FJ1200
89  FJ1200

krusty

Have you serviced or checked the slave cylinder? It can get a bit grotty down there. The piston could be sticking due crud or corrosion or both.
91 FJ1200
84 FJ1100 x 2
85 FJ1100
89 GL1500
76 CB750F1
72 CB350F
63 C92 x 2
59 C76
62 C100
63 C100
60 Colleda 250TA x 3
63 Suzuki MD50
77 DT125E
77 DT175E x 2
79 DT250F

FJ_Hooligan

When a clutch is worn out, it means the plates have worn so much that it doesn't "lock up" well and thus slips under load.

What you're describing is the opposite.  That means the plates are not getting separated enough and it's causing the plates to drag which makes shifting difficult.

25 thousand miles is NOTHING for these bikes and their clutch.  I hardly think it's worn out unless it's been horribly abused.  One member had over 250,000 miles on his original clutch.

I once tried an FJR clutch master cylinder on my '85 FJ and it was useless.  It did not push enough fluid to disengage the clutch and caused noticeable drag that made shifting difficult at best.  I switched back to the original master cylinder and everything went back to normal.

I'd suggest going back to your original MC and see if that helps.  Also, check the slave cylinder for leakage or corrosion.
DavidR.

Bones

Have you adjusted the span on the lever, I've got mine on number 1, number 5 has the lever sitting too close to the grip and doesn't have enough throw to release the clutch properly.
93 fj1200
79 suzuki gt250x7


Too young to be old but old enough to know better.

TomJK

Hi
Usually needs bleeding...
Cheers, Tom
Past bikes : BMWR90-S,BMW R100CS, Ducati 900SD, Kawasaki GPZ600,Yamaha FJ1200,Kawasaki ZZR 1100 (4x),Kawasaki ZZR1200, Honda CBR1100XXX,Yamaha Thunderace, Kawasaki ZX10R (3X),
Aprillia Falco,Honda CBR600F4I, bikes today : Kawasaki ZX10R (C1, the best!),Yamaha FJ1200, soon to come Kawasaki Z900.....

fj-f3a

Recently, I renewed the friction discs of the clutch in my 91.

I was having the exact opposite problem, the clutch dragging making it impossible, not almost, to find neutral with the engine running.

Upon removal of the clutch side cover, I actuated the clutch lever and observed the action of the pressure plate.

What I noticed was interesting. The plate did not remain perpendicular to the axis of the push rod. Instead, it twisted and, for want of a better way to describe it, the edge of the pressure plate remained in contact with the clutch pack.

At our last man shed day, we installed a second diaphragm spring as suggested on this site to prevent the clutch slipping. I started having problems about three months later.

The old friction discs measured 3mm in thickness, worn 0.1mm. This equates to a total pre-load loss of about 1.5mm.

1.5mm is approximately half the travel of the slave cylinder with the OEM 16mm master cylinder.

Now, we all know that the Total Travel of the slave cylinder remains constant, owing to the design of the hydraulic system with the balance port but, this is not the important thing here.
What I believe is important is the removal of pre-load from the spring as the pack wares and again, for want of a better way of explaining it, the subsequent lengthening of the spring.
IMHO, this tends to make the twisting action more pronounced.

So, for what it is worth, after checking the usual suspects, master and slave cylinder seals, brass bush, corrosion in the slave cylinder and, most important, that the balance port is indeed open when the lever is released (this can be ascertained by observing a spurt of fluid from the port when the lever is first actuated), don't hesitate to replace the friction discs and if necessary, the steel plates. Stop looking for a "Quick Fix". Changing the clutch pack is quick and not all that expensive.

If you have greatly increased the HP of your bike, you may need an extra/ heavier springs.
Again, IMO, more discs would be a better alternative but, unfortunately, this is not possible.

I did do the Barnett conversion and all problems are solved. The lever is quite high and will take some getting use to. Also, I used the heavier springs because I thought they would be advantageous towing my trailer.

Like the original pressure plate, I noticed that the Barnett plate did not remain perpendicular to the axis of the push rod when the clutch was released. I have an idea for this and will keep you all informed.

BTW, even the Hays manual mentions one possible clutch problem is a Spring which has become uneven in its tension.

Just my Two Bob's worth.

Gavin
Wings Level

Current
1990 FJ1200, Wet Pale Brown
J17xMT5.5 rear wheel from a 2001 Kawasaki Zx9r
Stainless exhausts
Electronic cruise control
Custom seat
Yamaha R6 Blue Spot Callipers
FJR1300 Master Cylinder
Stainless brake lines

Tapartacus

Wow lots of info there! Thanks everyone, will consider all options. I thought I would start here for some suggestions as my local bile shop wants 900 bucks(Canadian) to replace clutch! Thanks again will report back.
Andrew
92  FJ1200
89  FJ1200

Bill_Rockoff

That would have been a frustrating use of $900, since it wouldn't have solved your problem at all, it would only have replaced some perfectly-good parts with other newer also-perfectly-good parts. That never helps anything.

If your motorcycle shifted easily with your FJR master cylinder for the last 10,000 miles, and only recently stopped shifting easily, that doesn't sound like a problem caused by changing to an FJR master cylinder 10,000 miles ago. (If changing to the FJR master was the problem and changing back to the FJ one was actually the solution, you would have noticed worse shifting immediately after you finished installing the FJR master cylinder, not 10,000 miles later.)

Topping up the fluid helps, but there's still air in the line. I have had good luck wiggling the flexible part of the line to get the air bubbles to rise to the top.

This is a temporary solution, of course, because there shouldn't be air in the line at all, and there shouldn't be a low fluid level. What you probably need is to replace the clutch slave cylinder seal.
http://rpmracingca.com/proddetail.asp?prod=Clutch%3AS%2FK
It's an inexpensive part (twenty bucks US) that is known to have kind of a short service life on these bikes. When it fails, it causes the two exact symptoms you described (low fluid level, harder to shift) plus a third symptom you probably have but either didn't notice or didn't mention (soft lever.) When I commuted on my bike in summer traffic, I was replacing that seal about once a year for a while, I think I've done it seven or eight times on my bike, including an entire master cylinder replacement one of those times. The seal gets brittle and hard after a few years, which is why it causes this problem in the first place, so be careful when removing the old one not to cut yourself or scratch any shiny surfaces prying it out or cutting it apart in place to remove it.

It is SUCH a common FJ issue that I am surprised nobody has already suggested it here already.

By which I mean, I am "surprised" the same way I would be "surprised" if you mentioned that your motorcycle doesn't corner very well after 5,000 miles on your current tires, which you have noticed are somewhat flatter across the middle than you remember them being, and your local shop has quoted you $3,000 to replace the wheels, and all these wise and knowledgeable FJ folks chimed in with advice like "maybe it's your air pressure, try adding more air" and "have you tried upgrading to wider wheels? I put a 17x5.5 GSXR wheel on mine and now it corners like a GSXR" and "how are your wheel bearings? you may need new wheel bearings, I measured mine once and found that I needed them because mine twisted in a barely-measurable way" and I am wondering "Jesus Christ, it needs TIRES, how is nobody else seeing that? I can't be the only one who thinks it's probably just that the rubber part that always wears out has worn out, and it's simply time to replace the worn-out rubber part that always wears out with a new unworn rubber part?" Somehow "surprised" doesn't cover it, really. None of my kids ever smeared feces on the wall or poked metal things into electrical sockets, but if they ever did one of those things - particularly now, given that they are adults with jobs and their own homes and families - I imagine that whatever I would feel in addition to "surprised" (horrified? dismayed?) is pretty close to how I feel reading the suggestions we have compiled for you here in this thread that have somehow all managed to miss the most likely answer.

Replace that $21 slave cylinder seal. Clean the hydraulic piston and cylinder surfaces with brake cleaner while it's apart, because crud (or even a bit of corrosion) can build up there. If you ride in traffic or in hot weather, you will need to do this again in 10,000 miles, so maybe buy two and have one for next time.
Reg Pridmore yelled at me once


Old Rider

One more tip you MUST try: Tie the lever into handlebar overnight ...  Do the same for brakelever  you will be surpriced..
If it helped then you know it was because of air in the system. If the problem comes back fast you got an airleak in the master cylinder or at the slave cylinder seal or in the bleedscrew

krusty

Quote from: Bill_Rockoff on August 19, 2020, 06:51:55 AM
That would have been a frustrating use of $900, since it wouldn't have solved your problem at all, it would only have replaced some perfectly-good parts with other newer also-perfectly-good parts. That never helps anything.

If your motorcycle shifted easily with your FJR master cylinder for the last 10,000 miles, and only recently stopped shifting easily, that doesn't sound like a problem caused by changing to an FJR master cylinder 10,000 miles ago. (If changing to the FJR master was the problem and changing back to the FJ one was actually the solution, you would have noticed worse shifting immediately after you finished installing the FJR master cylinder, not 10,000 miles later.)

Topping up the fluid helps, but there's still air in the line. I have had good luck wiggling the flexible part of the line to get the air bubbles to rise to the top.

This is a temporary solution, of course, because there shouldn't be air in the line at all, and there shouldn't be a low fluid level. What you probably need is to replace the clutch slave cylinder seal.
http://rpmracingca.com/proddetail.asp?prod=Clutch%3AS%2FK
It's an inexpensive part (twenty bucks US) that is known to have kind of a short service life on these bikes. When it fails, it causes the two exact symptoms you described (low fluid level, harder to shift) plus a third symptom you probably have but either didn't notice or didn't mention (soft lever.) When I commuted on my bike in summer traffic, I was replacing that seal about once a year for a while, I think I've done it seven or eight times on my bike, including an entire master cylinder replacement one of those times. The seal gets brittle and hard after a few years, which is why it causes this problem in the first place, so be careful when removing the old one not to cut yourself or scratch any shiny surfaces prying it out or cutting it apart in place to remove it.

It is SUCH a common FJ issue that I am surprised nobody has already suggested it here already.

By which I mean, I am "surprised" the same way I would be "surprised" if you mentioned that your motorcycle doesn't corner very well after 5,000 miles on your current tires, which you have noticed are somewhat flatter across the middle than you remember them being, and your local shop has quoted you $3,000 to replace the wheels, and all these wise and knowledgeable FJ folks chimed in with advice like "maybe it's your air pressure, try adding more air" and "have you tried upgrading to wider wheels? I put a 17x5.5 GSXR wheel on mine and now it corners like a GSXR" and "how are your wheel bearings? you may need new wheel bearings, I measured mine once and found that I needed them because mine twisted in a barely-measurable way" and I am wondering "Jesus Christ, it needs TIRES, how is nobody else seeing that? I can't be the only one who thinks it's probably just that the rubber part that always wears out has worn out, and it's simply time to replace the worn-out rubber part that always wears out with a new unworn rubber part?" Somehow "surprised" doesn't cover it, really. None of my kids ever smeared feces on the wall or poked metal things into electrical sockets, but if they ever did one of those things - particularly now, given that they are adults with jobs and their own homes and families - I imagine that whatever I would feel in addition to "surprised" (horrified? dismayed?) is pretty close to how I feel reading the suggestions we have compiled for you here in this thread that have somehow all managed to miss the most likely answer.

Replace that $21 slave cylinder seal. Clean the hydraulic piston and cylinder surfaces with brake cleaner while it's apart, because crud (or even a bit of corrosion) can build up there. If you ride in traffic or in hot weather, you will need to do this again in 10,000 miles, so maybe buy two and have one for next time.
See reply #5.
91 FJ1200
84 FJ1100 x 2
85 FJ1100
89 GL1500
76 CB750F1
72 CB350F
63 C92 x 2
59 C76
62 C100
63 C100
60 Colleda 250TA x 3
63 Suzuki MD50
77 DT125E
77 DT175E x 2
79 DT250F

Millietant

I like your choice of words Andrew - if a shop wanted me to pay 900 buck (Canadian) to replace my FJ clutch, I'd call them a BILE dealer too.......that's a ridiculous amount of money and it seems like they haven't even mentioned the easy/obvious issues that could be tried for just a few bucks (Canadian).

As others have said a failing, worn out, clutch is usually a slipping clutch. Your problems definitely seem more likely to be due to air in the system, a leaking slave cylinder seal (as per Krusty), or possibly, but unlikely, a leaky master cylinder seal. If it was my bike I'd take off the slave cylinder and replace the seal (and give everything a thorough clean), then thoroughly bleed the system to make sure there's no air in it. If that didn't cure it, I'd refresh the master cylinder seals (another low cost kit) and bleed again...but, by the time I got to this, I might already be thinking about changing the original clutch hose (probably old and spongy) for a braided stainless steel one (again the cost is in multiples of 10 bucks, not 100's of bucks).

The most difficult of part of all of this is making sure the system is properly bled. I had a nightmare doing mine last time, until I used a small hand pump to push fluid through the bleed nipple on the slave cylinder, back up to the master cylinder.......problem solved and system devoid of air in about 20 seconds.

This is the pump I use (the brand is Laser), again it cost just a few pounds/bucks. Best of luck and hope you get it sorted quickly and cheaply  :good2:

Quote from: Tapartacus on August 18, 2020, 05:55:21 PM
Wow lots of info there! Thanks everyone, will consider all options. I thought I would start here for some suggestions as my local bile shop wants 900 bucks(Canadian) to replace clutch! Thanks again will report back.
Andrew

Dean

'89 FJ 1200 3CV - owned from new.
'89 FJ 1200 3CV - no engine, tank, seat....parts bike for the future.
'88 FJ 1200 3CV - complete runner 2024 resto project
'88 FJ 1200 3CV - became a race bike, no longer with us.
'86 FJ 1200 1TX - sold to my boss to finance the '89 3CV I still own.