I had the clutch cover off and am struggling to understand how the clutch actuator works.  Every bike I remember controls the bike from the opposite side of the engine.  A rod goes through and pushes the pressure plate out to create clearance and release the clutch.  On this bike, the slave cylinder pushes in the opposite direction.  So, is the movable pressure plate on the back side of the clutch pack when compared to other bikes?  The parts list looks like that.      

Not unusual really, same as TLR's albeit they are cable operated...... 

Take a look from 4-42 to 4-45 of the service manual.  should help enlighten how the clutch works.  (2020 301 RR service manual: https://www.montesa.com/wp-content/uploads/2020/03/OSM-301RR-2020-EN-Web_V04.pdf )

Thanks for the clarification.  I was installing some spacers to reduce spring preload.  I planned to pop the plates out to see if it had dimpled plates but was surprised that the plates could not just slip out.  It is sort of the reverse of every other bike clutch I have ever had apart.  I learned something new.  

like you said it works the reverse way, the springs push the plates out to the pressure plate on the end, when operated the pressure plate pushes toward the engine and releases the clutch. I've only ridden a few 4RT's and found the clutch to be of a light action so I would compare yours to others before adjusting the springs. It may be you have another issue

There are springs and plate available which improves the clutch feel. of course it`s only available in Japan. 

Edited November 15, 2025Nov 15 by lineaway

The plate holds the springs straight. They other wise rub

on the towers. The springs are much lighter. Available from Webike.

Personally I think you are trying to improve the best clutch in the industry.  Hasn't been mentioned yet but there are 2 types of friction plates in the Cota clutch, 3 corks and 2 paper, the consensus was the paper plate gives the clutch more bite, or absorbs less oil and exhibits less compression, depending how you look at it.  Key to making the clutch pull lighter is not to weaken the clutch but to improve your clutch actuator leverage at the levers, the further you hold the lever out from the pivot point the more leverage you have against the hydraulics and the greater your friction range is.  

The 4RT 301RR makes  a pathetic 16.3 HP , 1 HP more than a VERTIGO 125   but the 301RR puts out 15.1 ft/lbs torque  , where as the VERTIGO 125 makes 8.8 ft/lbs . With that much torque output of the 301 it may be better leaving it with the stock clutch spring set up.

4RT 260 makes 15.6 HP and 13.4 ft/lbs torque

Edited November 16, 2025Nov 16 by Tr1AL

19 hours ago, lemur said:

Personally I think you are trying to improve the best clutch in the industry.  Hasn't been mentioned yet but there are 2 types of friction plates in the Cota clutch, 3 corks and 2 paper, the consensus was the paper plate gives the clutch more bite, or absorbs less oil and exhibits less compression, depending how you look at it.  Key to making the clutch pull lighter is not to weaken the clutch but to improve your clutch actuator leverage at the levers, the further you hold the lever out from the pivot point the more leverage you have against the hydraulics and the greater your friction range is.  

There is a reason the hrc machines use a different clutch.

1 hour ago, lineaway said:

There is a reason the hrc machines use a different clutch.

any particular reason you made that a reply to my post or is that just a habit 🤔

 You were repying to me, again! LOL

The Montesa clutch has never been very good ever. But we all have opinions. You should know better. Don't you ride a TRS now?

 

10 minutes ago, lineaway said:

 You were repying to me, again! LOL

The Montesa clutch has never been very good ever. But we all have opinions. You should know better. Don't you ride a TRS now?

 

Yes 2 and experienced a failure in a TRS clutch O-ring already.  The clutch is not up to par with HRC Cota 315 or 4RT, I have to keep it engaged or it sounds like a bag of bolts.

That is 'nornal' on a diaphram clutch! The oring should not go bad if you are using mineral oil. Must be that tractor lube!

21 minutes ago, lineaway said:

That is 'nornal' on a diaphram clutch! The oring should not go bad if you are using mineral oil. Must be that tractor lube!

Yes that normal trashy clutch sound in neutral the 5 plate Montesa clutch does not exhibit, the TRS o-ring fail was very early after receipt of the bike, was leaking down from the start.  Fortunately I rarely have clutch problems with any of my vehicles, that tractor lube works perfect, you just never even tried it to know better.