Clutch pull modification

13 replies to this topic
  • Quik426

Posted August 17, 2004 - 04:05 AM


Just thought I'd pass along a little info on something I tried.... I have been running a Revloc clutch in my '02 426 and decided to try the original stock clutch setup again. I race and it seems that when I had the Revloc clutch installed, that the bike wanted to "push" through the corners and felt a bit unstable. So....... I put the stock clutch back in but left out 2 of the bolts and springs of the 6 that are used to hold the pressure plate against the clutch pack. I was a bit concerned that the clutch may slip under startline launches or deep boggy racing but it worked great!! Even to the point that I managed a holeshot against 22 other riders!!
I have lengthened the clutch arm also, but with the reduction of the 2 springs and bolts.... :thumbsup: The clutch pulls very easy and doesn't give me arm pump.
A bit more info.......IF you want to try this mod, be sure that you remove the bolts opposite of each other. This ensures that the clutch will still be in "balance" when it's spinning.
I'm currently setting up my son's 250f for this but it's a bit different in that, it only has 5 bolts holding the pressure plate. I've found some small washers that will fit inside of the springs and around the bolt that will "space" the bolt from tightening down as far. This should relax the springs a bit and make the clutch pull easier. I haven't tried it under track conditions but the pull is definately easier. I will let you all know after the races this weekend if it worked out. IF it does I will stop by the 250 side of this website and let them know how it works....

Quik :devil:

  • Fastest1

Posted August 17, 2004 - 09:09 AM


I suspect clamping pressure will be a problem eventually.

  • Davidyz450

Posted August 17, 2004 - 09:26 AM


I agree! I think it will definitely cause problems in the future. Especially racing. It's almost like putting weaker springs in. The overall surface clamping force is reduced.

  • Fastest1

Posted August 17, 2004 - 09:35 AM


BTW how much feathering are you having to do? These bikes have a lot of power throughout the rpms so why? It isnt a 2 smoke! Also if done extensively it will build up quite a bit of heat.

  • Quik426

Posted August 17, 2004 - 09:45 AM


Don't shoot the messenger..........just thought I'd let you know what I've tried and if it's working for me.
I agree that clamping pressure is reduced but a stock clutch produces approx 350 psi lock up force. I was also concerned that it may slip or not work at all but the test was.... this past weekends racing and I'm quite pleased with the results.
You are welcome to try it..........or don't if you think that there are too many negatives. I change my oil after every third race/ride, which is about 3-5 hours of operation and have only run this for one race I said, I will let you know if I have any problems in the future with mine or my son's 250F.
I'm not that knowledgeable on "slipper" clutches... but I think this would be similar.... :thumbsup:

just sharing info........ :devil:

Quik :awww:

  • Fastest1

Posted August 17, 2004 - 11:48 AM


I agree, it was worth a try for sure and the results seem good. If you are racing, clutches are just normal replacement items anyway. If you cant afford the 100 bucks or so then you couldnt really afford to race. Let us know how it works in the long run. Why did you remove the Revloc? Did it improve your results with out it. I really dont see the auto as an advantage in mx. I use one but I dont race, just play. In the woods or trails they are fantastic.

  • Quik426

Posted August 17, 2004 - 02:22 PM


Thanks for the positive input!! :devil: I have ran the Revloc for racing for nearly 1 1/2 years and it has worked well in several occasions.....especially when you crash and the bike is laying on it's side waiting for you to pick it up and take off again!!! But like I said in my first post, it felt like the bike "pushed" and didn't want to corner very well so I thought I'd give the stock clutch a try again. I guess I need to preface this with the fact that I'm a "C" or novice rider and am always looking for anything that may help in my quest to be better.....
In some of the previous posts........"in the long run you will have problems"..... let me say this.... you will wear out parts no matter what you do!!! :thumbsup: Clutches will wear, parts will wear ....everything wears>>>in the long run!!! I'm only passing along things that I'm trying and it may not work for what you do.... For trail riding, the Revloc is super!!! :awww: I still have both the stock set-up and the Revloc for each occasion.
I only hope that if others try this out on their bikes that they will come back here and continue this post and let everyone know their opinions :lol:!!!
If you race........I think this is something you should try for at least a practice if not a race.... you can always put the 2 springs and bolts in, in nearly 10 minutes if you aren't happy or have negative results.

Just come back here and let all of us know if you tried it and what you think!!


Quik :D

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  • Hamish

Posted August 18, 2004 - 04:39 AM


I just put a pivot assist perch and a teflon cable into my Wr426 with excellent results. Ultra light clutch feel, but more lever travel is required to disengage the clutch fully. But over all I give it the :thumbsup: The perch appears the same as the stock unit, but the hole in the lever where the cable end locates is closer to the pivot point, giving a better purchase.

  • Quik426

Posted August 18, 2004 - 05:09 AM


I already have MSR Raptor levers installed on both of our bikes which are designed the same way. They have 3 different attachment locations for the cable. I'm just trying new things with removing the springs and bolts. I don't think that you would want to do this to your bike if you trail ride all/most of the time.

Like I said, hopefully those who try removing the bolts and springs.....come back a let us know what you think!!

Quik :thumbsup:

  • Satch0922

Posted August 18, 2004 - 05:57 AM


What is the clutch for?? LOL

  • Chris_from_Oz

Posted August 18, 2004 - 07:11 AM


What is the clutch for?? LOL

:thumbsup: :awww: :devil:

  • Quik426

Posted August 18, 2004 - 09:24 AM


Come on guys.... :thumbsup:
If you were aware of Revloc's design, then you would know the clutch is still useable. I used it for startline launches and various other situations.......

Quik :devil:

  • tool

Posted August 20, 2004 - 03:53 PM


all i know is, my favorite thing about my z-start is the lack of lever pull. the lever barely stays extended, just jiggles a bit.
my 2nd favorite thing about the z-start is it makes you lazy, really lazy; even in MX. its like i could downshift, but i wont. the bike always pulls.

  • Quik426

Posted August 24, 2004 - 03:49 PM


It's me again........the weekend of racing with the two springs and bolts removed was a sucess again for the 426... but the mod on the 250F didn't work out as well. Must be the 5 Bolt arrangement or other issues with the 250F.

My only info is that you should at least try taking out 2 opposite bolts and springs and see if it works for you... and come back and post results if you've tried it!!


Quik.... :thumbsup:

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