I haven't gotten the Gen1 slave cylinder yet, and I do agree that can't help reduce the pull of the lever. I was wondering if there is adjustable clutch rod in between the slave cylinder and the clutch? So I can adjust it out to the point before it starts disengaging the clutch? I have done that on some cars.
This came up in another context some weeks ago, when Nitrotate was adapting the clutch system to the T-Rex style trike he's building. His clutch pedal moved the clutch too far, and he actually inverted the spring discs, something like that. but in the discussion was the question of changing the length of the actuator arm in the slave cylinder.
Wouldn't work, it would just change the rest position of the clutch. When the spring stops clamping the clutch (pushing the slave cylinder's piston back into the cylinder) the piston stops. There's no gap to adjust.
Wouldn't work in your case, either. If you tried to use a longer piston rod, it would just push the piston farther back, and the next stroke would have the same amount of motion as stock. If you had a rod long enough it couldn't go back any further, then you've pre-loaded the clutch and kept it from engaging completely, leading to slippage and clutch wear.
Only two places to adjust clutch travel versus lever travel. First is the relative diameter of the hydraulic cylinders, and as has already been pointed out, the larger diameter slave of the earlier models gives you a softer effort, but at the expense of a longer throw. The other place to adjust is the length of the throw arm on the clutch lever. How far is it from the lever's pivot point to the end of the piston going into the master cylinder? The stock lever has no adjustment for that. Maybe the Pazzo levers do, I don't know, or maybe they're just different to begin with. Making that distance longer would give more clutch action for the amount of lever action, but at the expense of higher effort.
It's all about leverage, and you can't shorten the motion without increasing the effort, nor can you decrease the effort without lengthening the motion.
I think what you're fighting here is just that the FJR, with more than twice the displacement of your R6, simply has a bigger, beefier clutch assembly. It doesn't have to take the revs that the R6 could throw into a clutch, but it has to take more torque. A little more diameter, bigger plates, thus a stronger spring for clamping force.