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FJ1200 clutch not fully disengaging, new slave kit

Started by Tekime, August 31, 2016, 12:05:29 PM

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My FJ was leaking some fluid from the clutch slave and shifting hard. Ordered the slave rebuild kit from RPM.

Installed it last night very carefully, and did the syringe "trick" to force fluid in. Just kept getting air. So I filled the reservoir and pumped the clutch lever, opening the bleed nipple each time. Did this 7-8 times until there were zero air bubbles. Then left it with the cap loose overnight.

I'm still getting a ton of clutch drag, very hard to shift, and the rear wheel is turning slowly when in 1st on the center stand with the clutch pulled in.

Lever feels like it has good resistance.

Did I just do a poor job of bleeding it? Or would you look elsewhere (master cylinder, pushrod, etc.)

The clutch lever does feel firm but it has a little slop at the very start, it has since I bought it, like 1" of play or so.


One inch or so of free play at the lever is too much. You may still have air in the system, although you may think that you got it all out.

You may also need a new spring on your clutch assembly too. How many miles are on your bike?
Platinum Zircon-encrusted Gold Member

Iron Balls #00002175


Okay, maybe I spoke too soon. I started her up and it seems to be shifting better now. Just took it for a spin and shifted through the gears without much fuss, although neutral is a bit hard to find. It feels more or less like it did before the leak, so I'm less concerned about air bubbles now.. but still thinking about another bleed with a vacuum pump.

It does feel like it's not *fully* disengaging, as in just a hair more and it would be perfect, but the clutch lever is all the way to the handlebar so I can't go any more!

Bike is at 54k or so, no idea on the history so I assume everything is stock if I haven't replaced it myself. :)

You're referring to the M/C rebuild kit?


Quote from: Tekime on August 31, 2016, 01:02:10 PM
You're referring to the M/C rebuild kit?

No the spring inside of the engine cover, that has the engine oil level sight glass on it.
Platinum Zircon-encrusted Gold Member

Iron Balls #00002175


Quote from: Tekime on August 31, 2016, 01:02:10 PM
but still thinking about another bleed with a vacuum pump.

It does feel like it's not *fully* disengaging, as in just a hair more and it would be perfect,

Using a vacuum pump bleeder is the ticket for getting the clutch perfect.

For the "not fully disengaged" feeling. This could be a few separate or accumulative things.

up at the clutch master.....
check the pivot point on your lever for wear.
Check that there is no fluid weeping past the piston seal.
Make sure the adjustment is as far as you can get it.....You want the lever to have the max amount of movement.

You have already covered the slave cylinder. If it is leaking fluid, it is getting air in the system.

I had a similar issue with a neutral being difficult to find and very notchy downshifts. I would vacuum bleed the system, and all would be great. 2 weeks later, back to hard to find neutral, difficult downshifts, and the bike wanting to creep at stop lights. Someone with a vast amount of FJ knowledge shared a nugget.

Each clutch fiber disc has a minimum thickness value. As the fiber discs wear, (say .01mm each) the wear of the clutch is multiplied by 8. The slave cylinder piston has a finite movement. It can only move as far as the amount of fluid displacement, which is a constant. In the perfect world, you bled the clutch with new fiber discs. Once all of the fluid is moved and the slave piston is in the full extended position, everything disengeges and the clutch is released.

Now for the notchy shifting and the hard to find neutral. As the discs wear, the slave piston is needing to travel further to disengage the discs using the same amount of fluid. When the accumulative wear on the fiber discs gets to the point that the slave piston is at it's max travel.......You get a rear wheel that slowly turns in gear with the clutch handle against the hand grip.

With a Well functioning clutch system, this is an indication that a new set of fiber discs need to be ordered.

I hope this all makes sense.....and helps. :flag_of_truce:

I'm not the fastest FJ rider, I am 'half-fast', the fastest slow guy....

2008 VFR800 RC46 Vtec
1996 VFR750 RC36/2
1990 FJ1300 (1297cc) Casper
1990 VFR750 RC36/1 Minnie
1989 FJ1200 Lazarus, the Streetfighter Project
1985 VF500F RC31 Interceptor


Quote from: Tekime on August 31, 2016, 12:05:29 PM
... it has a little slop at the very start, it has since I bought it, like 1" of play or so.
You need to look at the clutch lever & bushing as well.

Randy - RPM
Randy - RPM


I don't understand that description at all.  The clutch spring loads the pressure plate against the plates.  I would think when the fiber plates wear, the pressure plate would move toward the slave cylinder slightly uncompressing the spring (slightly) and requiring progressively less clutch lever stroke to disengage.  

This could cause the level of fluid in the master to actually increase as the clutch wears.  As the plates wear, the spring pressure gets less therefore requiring less of a clutch lever stroke to release the clutch.  Theoretically, the plates would wear out completely such that the spring is fully uncompressed.  At that point, the lever stroke required to disengage the clutch is zero.  

Plate wear doesn't cause the clutch to "drag" rather, it makes the system more prone to slip.  

It sounds like the OP's problem is on the fluid side.

I may have this wrong, it's been a long time since I've had my clutch apart.


The clutch tends to self bleed, I have tested this when I swapped out my master. I simply swapped the masters out, and cycled the clutch lever and watched the bubbles rise up and out of the master reservoir. It has worked perfectly since then.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side


Thanks for all the info. Extremely helpful!

I checked out the pivot bushing and clutch lever for wear. Looked good with no obvious wear, but there was still that play in the lever. Suspected I was losing a few mm in the pivot bushing or M/C somewhere, possibly from wear but not noticeable to the eye.

Ground a small ~2mm length of stainless screw and dropped it in the pivot bushing. Cleaned the whole area up, touch of lube and assembled.

Shifting smoother than ever now!! The clutch lever finally stays in one place and doesn't flop everywhere, has just enough play to be fully released and the spring keeps it snug.

M/C is definitely due for a rebuild; still doing its job/no leaks but dust seal crumbling and the spring is probably ancient.

On a side note, the previous owner said something about "did the clutch" and "not long ago" whatever that means. I vaguely remember him mentioning springs, so it's possible he dropped some stiffer springs in there. If so I'm thinking it might account for the left-hand fatigue, and possibly accelerated wear on the lever/bushing/MC. Clutch lever has always been a tough pull, similar to my enduro which has stiffer springs.


If he specifically said springS (plural) then he might have done a coil spring conversion.  Possibly the Barnett conversion unit. 

Most people who have done that report that the Barnett plates drag.  Switching back to stock Yamaha plates helps.