Fjr1300 clutch slave on an FJ1200?

[great white]

I've got the RPM oil filter kit on my FJ12 and now I need to replace the clutch slave (leaking, too pitted to re-seal). Before I order a new one from RPM and start cutting it down to better fit the remaining opening, does anyone know if an FJR1300 clutch slave will fit on to an FJ12?

If the mount ears are the same, I'm pretty sure the ports will end up in different locations.

Ideally, I would be able to use the FJR slave as I am using the FJR clutch master which is a 14mm bore as opposed to the FJ 5/8 bore (IE: 16mm). I dealt with the difference by machining a spacer to fit in the FJ slave body, worked fine. But if I could match an FJR slave with an FJR master I would not require the spacer.

Anyone tried it or know if it will/won't work?

[great white]

Well, looks like it won't go.

I wasn't worried about different depths as I would have just spun up and adapter. But when I grabbed some pictures of the FJ, FJR and even an FZR slave cylinder off ebay, then scaled them to the same size in photoshop and it appears the ports just won't go on the FJ. The FJR looks like the mount "ears" don't line up at all and the FZR while the ears match, the line and bleed ports are pointing right into the alternator housing.

So it's a new Fj slave for me......

[Pat Conlon]

Why not sleeve your FJ slave to get whatever piston size you wish?
http://www.fjowners.com/index.php?topic=12294.0

Cheers

[Sparky84]

Before I order a new one from RPM and start cutting it down to better fit the remaining opening,

If you get a new one, why the "cutting it down to better fit"?

Ideally, I would be able to use the FJR slave as I am using the FJR clutch master which is a 14mm bore as opposed to the FJ 5/8 bore (IE: 16mm). I dealt with the difference by machining a spacer to fit in the FJ slave body, worked fine. But if I could match an FJR slave with an FJR master I would not require the spacer.

I didn't think the slaves had a "bore" size..

Well, looks like it won't go.

I wasn't worried about different depths as I would have just spun up and adapter. But when I grabbed some pictures of the FJ, FJR and even an FZR slave cylinder off ebay, then scaled them to the same size in photoshop and it appears the ports just won't go on the FJ. The FJR looks like the mount "ears" don't line up at all and the FZR while the ears match, the line and bleed ports are pointing right into the alternator housing.

So it's a new Fj slave for me......

I wouldn't even attempt to use an ebay,
sorry but new is best or that sleeving looks good

Cheers
Alan

[great white]

Before I order a new one from RPM and start cutting it down to better fit the remaining opening,

If you get a new one, why the "cutting it down to better fit"?

Shape. Instead of a flat lower edge (where it would mate to the oem oil filter housing) I round the housing off so it looks less like something is missing.

Ideally, I would be able to use the FJR slave as I am using the FJR clutch master which is a 14mm bore as opposed to the FJ 5/8 bore (IE: 16mm). I dealt with the difference by machining a spacer to fit in the FJ slave body, worked fine. But if I could match an FJR slave with an FJR master I would not require the spacer.

I didn't think the slaves had a "bore" size..

Sure do. it's not a one sizer fits all thing. The Slave bore is matched to the master so you get the correct travel for clutch release. But, in order to reduce the slave, you need a resized piston face. In this case, it needs to be smaller so the 14mm master provides the proper fluid displacement for proper slave piston travel. Al my spacer does is reduce the absolute volume, it doesn't change travel. I'd have to sleeve the slave housing and fit a smaller piston. It's one of the principles that allows hydraulics to work as they do.

Well, looks like it won't go.

I wasn't worried about different depths as I would have just spun up and adapter. But when I grabbed some pictures of the FJ, FJR and even an FZR slave cylinder off ebay, then scaled them to the same size in photoshop and it appears the ports just won't go on the FJ. The FJR looks like the mount "ears" don't line up at all and the FZR while the ears match, the line and bleed ports are pointing right into the alternator housing.

So it's a new Fj slave for me......

I wouldn't even attempt to use an ebay,
sorry but new is best or that sleeving looks good

Your call. Nothing wrong with a used rebuilt. 20 bucks for seals or 100 bucks for a new master. Your choice.....

Cheers
Alan

Replies in red.

[great white]

So, all together and bled. Clutch works, but that 14mm master with the FJ slave means it doesn't disengage until the lever is a couple MM's away from the grip. Even then, it's just barely disengaged. You can feel it dragging a bit.

Basically, I need a longer stroke since the master went from 5/8" to 14mm with the FJR swap. I plan to keep the FJR master, since it matches the FJR brake master. I also like the adjustable lever on the FJR master.

So i put the lever adjuster on it's furthest away setting and then threw in a thin spacer to give a little more stroke before hitting the grip. Now the FJR master will disengage the FJ clutch without it back hard against the grip. But you still need to pull all the way to the grip to get a positive disengagement. And when you let the clutch out, it grabs immediately as you even just let pressure off the lever. Not to mention, the reach for the lever is just a little too far for my liking. I can use it just fine, but it's a full open palm reach to get my two fingers around it.

That's just not going to do. I can't ride with a clutch that is more an "on/off" switch than a progressive engagement. Yes, I know that's how most hydraulic clutches work. I am used to a more progressive feel.

So I need to find a way to reduce the piston size of the slave.

I could always sleeve the oem slave housing, bore it out to the desired diameter and spin out a new piston of proper diameter. then it's a matter of finding a seal that will actually fit this custom slave cylinder. Sounds like a nightmare at best.

So today, I ordered an FJR slave cylinder. Found it going cheap. This will allow me to take an FJR slave apart and take some measurements.  Then, I can decide if I want to modify an FJ slave, find a way to mount an FJR slave, or I might look to sleeve the OEM Fj housing and fit the FJR piston.

Unfortunately, FJR slave seals aren't available, at least not commonly like the FJ seal kits are. If I get really jammed up, FJOC at least sells a seal. Only pita is that the seal is  £39.99! After exchange (around 1.6 to 1 CAD) plus shipping (not to mention customs, duties, taxes, etc) will make that something like a 100 dollar seal......



So there it sits until my FJR slave shows up and I can sit down and do some serious figurin'.

Good thing I've got a metal lathe and mill in the shop.....

[FJ_Hooligan]

I had that same problem with an FJR master on my '85.  Not worth jacking with, went back to stock

[great white]

I had that same problem with an FJR master on my '85.  Not worth jacking with, went back to stock

It's all about the ratio of master to slave.

The FJR is a 14mm master, the FJ is a 5/8.

If you down size the master and leave the slave the same, you end up with needing more travel to move the same amount of fluid the 5/8" master did. The result is the lever has to come right back to the grip in order to move enough fluid to disengage the clutch.

There's a couple options to solve the hydraulic issue with clutch disengagement:

1. (as you did) install a 5/8" master

2. accept that the lever is going to have a longer stroke, or

3. reduce the diameter of the slave piston so the stroke of the 14mm piston moves the slave the proper amount.

I want to keep the FJR master, so I need to look at reducing the size of the slave piston to bring the ratio back to what the FJ originally uses.

I suppose the last (somewhat extreme) option woudl be to bore out a 14mm slave to accept the 5/8 piston assembly. That's within my wheelhouse, but it's in the "last option" category.

[great white]

Old post and I've been away a while, but I'll give an update in case anyone runs across this thread on a search looking for similar info.  

Bike has been sitting for a while as I work on other parts of it (and other projects around the house). But, I think I might have solved the 14mm master problem. An XJR1300 has a 5/8 clutch master and is the same form/shape as the FJR brake/clutch masters.

So I ordered up a used XJR master cylinder off ebay and once installed, it should return normal clutch action as well as matching the look of the FJR brake master on the other side.