Clutch issues

[ACM]

I have a 2014 RX, purchased NOS in 2018, I'm at around 18k miles right now. It has the non-functional low fuel light issue and I had to replace the front rotor for what sounds like the issues the early bikes had; the last few digits of the VIN are EE300310 if that helps. I have been running Motul 7100 since the first 600 mile service, I change the oil & filter every 3k miles and last thing at the end of the riding season - New England, so Nov or Dec, and riding again in April with a little luck.

This season I have started having clutch issues, they occur on rides lasting more than 200 miles; shortly after 200 miles I start having trouble finding neutral at a stop. As the miles progress I find the shifter completely immovable at a stop, never mind finding neutral, I simply cannot even change gear at all with the violence I am willing to inflict on the shifter. Shortly after that, maybe 250 miles or so, the clutch starts to drag and I have to use a brake to stop the bike moving forward. By 300 miles the rear brake can no longer hold the bike in check easily and I need to use the front brake to stop the bike moving forward.

I bled the system through with (fresh) Motul RBF600, and that definitely improved the action, but it didn't change the above symptoms, so I'm not sure where to go next. I don't have any experience with hydraulic clutches on motorcycles, all my other bikes since the 70's have had cable clutches, this is my very first hydraulic clutch, so I'm hoping there's a knowledge base here ?

Thanks,
Charles

[Cooter]

Sitting for 4 years is a bitch on a high performance motorcycle. Stock levers? One of 3 things is happening, but your results will be the same.

The lever isn't allowing the piston to return in the bore enough, the M/C piston is sticking, or your transfer port is clogged.

Look into the master cylinder and see theres two holes in the bottom. Look REAL close at the big hole and slowly activate the lever. You want to see the black piston seal pass the big hole, and return completely past it, back to open, as you release. If it's not returning enough or sticking it won't let fluid from the master into the line and won't have enough pressure to release the clutch.

The other hole (transfer port) is super small and needs to be cleaned out. A cheap set of Jewelers drills is perfect for this and can get the hard crust out, but I've had luck with a tiny needle, or thin stiff wire.

Depending on your mechanical ability:
The seal is fine so disassembly, sonic cleaning, and re assembly will be fine,
OR 19mm rebuild kits are cheap and almost universal,
OR just buy a new 19mm radial master that fits 7/8" bars. I probably have a stock EBR one if you want it.

FYI the Oberon clutch slave piston (Buell 1125 V2 cover is the same application) is an AMAZING upgrade that reduces clutch pull by HALF (I wrote a step-by-step thread), and upgrading to a high quality 19mm master like Brembo is very worthwhile as well.

Post up what you find.

[ACM]

Thanks Cooter - the levers are OEM, everything in the clutch system is still OEM. I was planning on changing to the Oberon slave, but that's on hold until I figure this issue out. I will be changing to ASV levers in the near future, but again, not until I figure this out.

[Cooter]

Good to know the info and smart move to try to fix it before modding it. Remember if you end up replacing the master, a nice master like a Brembo comes with it's own lever. Get a 19mm for 7/8" bars.

My moneys on that.

Could be something as simple as being low on fluid, but I assumed checked that first. You'd notice a leak, and should be flushing that fluid every year anyway right?

[LeesEBR]

Did this get resolved? Curious to know what it turned out to be.

[Cooter]

I'm curious too! Something has to be building and holding pressure in the line.

[ACM]

I haven't had chance to work on it yet - I have 2 bikes apart at the moment, I need to get one buttoned up before I start on the RX.

I do believe Cooter to be correct, I think the bleed port is blocked; there is no free play at all at the lever, the pin the lever operates against has no movement at all, it is rock hard. Since it operates on the same principle as a brake master cylinder I checked those on my other bikes and they all have a small but distinct play, they can be compressed by finger pressure at least a mm or 2. I will confirm soon as I can work on it.

On a related note, the OEM rebuild kit is $112 (!), replacement OEM lever is $98, and a complete clutch master cylinder (including lever & remote reservoir) is $190. I got a Nissan OEM rebuild kit from Carpimoto.it for $20 - with $24 shipping...

[Cooter]

I hope I'm right too. It's a lot easier to put a piece of wire in a little hole than buy all that!

[LeesEBR]

I believe the clutch is the same 3/4" (19mm) radial mc that the brake uses. I got a rebuild kit for a 2005-2008 Suzuki GSX-R1000, pn 59600-29820. They vary in price, the one I got was NOS Suzuki-branded kit for $24 on eBay, fit the brake mc perfectly.

My clutch does have a tiny amount of travel before I can feel the resistance of the fluid pressure.

-EDIT-
Here's one that's ~$25 with $16 shipping
https://www.carpimoto.com/en-US/4617_MCBK19N-Overhaul-Kit-for-Nissin-19mm-Front-brake-Radial-master-cylinder.htm

[ACM]

Quick update - the bleed orifice is completely clogged, it will take a drill to open it up, every wire I tried shoving through the port just bent. New m/c on order, I will break my rule and install the Oberon slave at the same time coz I'm lazy :)

[Cooter]

Or drill it out by hand and flush with fluid. Don't open the system yet, the pressure will help blast the debris from the hole.

The size isn't that specific but leave it very small. A complete jewelers hand screwdriver kit is less than $5 on e-bay and handy for all sorts of things like dirt bike jets... or carb jets on a POS El Camino that swallows rain through a hole in the hood you cut out just because you wanted to put a huge scoop on a old tired small block and now it's your daily because you took your van apart, again.
:headbang:.

Oops, I was digressing.

But a YES to the Oberon. It's pricy, but dang worth it 100%.

[ACM]

Ah yes - I see you missed the bit about me being a lazy bugger ? Once the bike's back up and running I'll work on the offending m/cyl. My concern is the risk of any sharp edges left by the drill that could damage the seals. It's OK if the seals fail instantly, not so good if it takes a few dozen clutch pulls before they fail.

Right now it's standing room only in the garage, there's not enough room to check tyre pressures. I need to get rid of my brother's Gold Wing - jeez those things are big !

[mustangtyson]

Look into the master cylinder and see theres two holes in the bottom. Look REAL close at the big hole and slowly activate the lever. You want to see the black piston seal pass the big hole, and return completely past it, back to open, as you release. If it's not returning enough or sticking it won't let fluid from the master into the line and won't have enough pressure to release the clutch.

The other hole (transfer port) is super small and needs to be cleaned out. A cheap set of Jewelers drills is perfect for this and can get the hard crust out, but I've had luck with a tiny needle, or thin stiff wire.


Not OP. But I have spent a good bit of time looking at the bottom of my clutch master cylinder. I cannot find the 2 holes. Could you post a picture or give more details of where the holes are? Are you saying you can see these holes on a bike with no disassembly. Just looking from underneath the clip-on?

[ACM]

Do you have a problem with your clutch ?

If you do please explain it in as much detail as you can. I have lots of problems with my clutch now (OP), not sure they're your problems.

Please describe them as precisely as you can - probably in a new post ?