FJR1300 Clutch Master Cylinder on FJ1100

[MattyFJ]

Hey Guys

My clutch master cylinder recently started leaking, and I'm debating on going for a rebuild kit from RPM or swapping it out for an FJR1300 unit.  The cost in the end is the same, but I've read the larger piston in the FJR unit makes for an easier time in traffic. 

My question actually has nothing to do with the master cylinder, but the control pod on the left side bar.  On the stock FJ1100 master cylinder, there's a tab which nests into a slot in the control pod to keep it from rotating.  On the 1100, this tab is a part of the master cylinder and is located at the TOP of the handlebar.  On the FJR1300 master cylinder, that little tab is on the FRONT of the bar (its facing the rider).  Since the control pod on this side has the choke lever, which tends to want to spin the whole pod if not secured, has anyone done this mod, and if so, how'd you keep the control pod from spinning?  Simply cut a new slot in the plastic? 

Thanks!

[Steve_in_Florida]

Welcome to the world of mods!

Cutting a hole seems reasonable, based on your description. Measure twice, cut once.

Steve

[Arnie]

Those locating pins on the controls drive me crazy.
The best thing you can do is grind or file them off.

Then, you can adjust the control or switchblock to where YOU'RE comfortable.
Also, when you drop your bike (at high or low or no speed) the control can rotate rather than break.
Once you pick the bike back up just loosen the screws slightly and rotate it back to where you want.

[Pat Conlon]

Yes, notch the plastic so that the switch housing mates to the male nub on the m/c clamp. This was needed on my '84 which has the choke collar.
Without it, when you activate the choke (by rotating the collar) the switch housing would move. So the notch is needed to anchor the housing.

84/85's had the choke collar...I'm not sure this notch is needed on the '86-93 switch housings that don't have the choke collar. Still, it's a good idea.

When you cut the notch, put a glob of silicone in the opening before you slide the nub into the notch...helps keep your electrics dry.

[FJ_Hooligan]

My clutch master cylinder recently started leaking, and I'm debating on going for a rebuild kit from RPM or swapping it out for an FJR1300 unit.  The cost in the end is the same, but I've read the larger piston in the FJR unit makes for an easier time in traffic. 

Sorry to be a nerd, but I'm a stickler for technical accuracy.

The FJR master cylinder has a smaller piston.  For a given amount of force from the lever if it is applied to a smaller piston the result is a higher pressure in the fluid.

[FJmonkey]

Sorry to be a nerd, but I'm a stickler for technical accuracy.

The FJR master cylinder has a smaller piston.  For a given amount of force from the lever if it is applied to a smaller piston the result is a higher pressure in the fluid.

No need to apologize for being a Nerd, I am sure there are many here that proudly fit in that category. If the pivot points are the same or very similar with the lever and piston then your hand is pushing against a smaller amount of fluid (smaller piston). This means the amount of force required to create the same amount of pressure is reduced. It also reduces the amount of fluid being moved due to the smaller piston, but this does not seem to be an issue as the clutch and brake systems are still working properly with this change. It really is mechanical advantage but translated into fluids. If you are familiar with lever arms then the concept is the same, as the lever arm is lengthened, less force is needed to move the object and you get less amount of movement. 

[fj johnnie]

 Right you are monkey man. I just switched to a VFR master cylinder and each time I get on the bike I think the clutch needs to be bled, it is that much easier to use. Never thought I would want an easier clutch pull but last winter in New Orleans in stop and go traffic my arm got sore. That's when I remembered all the talk about clutch master cylinder swaps. As I had one on a shelf I decided to try it. I recommend a master clutch swap now.

[FJmonkey]

My new to me '89 has a much stiffer lever then my stock '86. Not sure it its a double spring or Barnett pressure plate. But I have a 14MM master that was donated to me by a fellow member that I might install before the WCR, the harder pull is quite annoying...

[aviationfred]

For those that like the urine cup style, the Honda VTR1000 (Super Hawk) and the Honda RVT1000 (RC51) clutch master cylinders will also work.

I know the Super Hawk Front brake master cylinder has a 17mm bore.


Fred

[Pat Conlon]

I thought the idea was to go with a smaller piston for the easier pull.
The oem FJ m/c is a 5/8" piston (16mm) so why would I consider using a m/c with a larger 17mm piston?

[edit] oops, never mind...Fred was talking about the Hawk front brake m/c, not clutch.... as you were.