how to fix MOST clutch problems + cr250r clutch conversion.

stainlesscycle

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ok, i figured i'd put all the data in one place.



cr250r clutch pack conversion:

stock gg friction plates: 2.85mm (some are 2.9mm)
stock gg steel plates 1.5mm

use honda cr250r 1994-2007

cr250r friction plates 3mm
cr250r steel plates 1.5mm

cr250r plates, clutch stack height = 30mm
gg plates, clutch stack height = 28.95mm

no mods need to be done to use cr250r steel plates.

to use cr250r clutch friction plates:
you can mill the inner clutch hub spacer (gg #ME25632011). You want to mill the one between the hub and the basket (not the one behind the basket) to between 1.80mm and 1.95mm (stock is 2.8mm - 3.00mm depending on year?) thick - mine is 2mm - and it drags slightly. i fixed this with 2 stock gg friction plate in the mix. you can adjust the clutch drag by mixing and matching stock and cr250 frictions. with bike running or not, hot or cold, i can put bike in gear, pull clutch and push bike around....with stock clutch, it would drag badly, and would not allow this. keep in mind there's a fine line between dragging and slipping. if your stack height gets too thin, it will slip. but when it's just right it's perfect...

if you don't want to mill the spacer, i believe suzuki part #08211-22423 is already 2mm thick (confirmed 2mm thick by bitoman) kawasaki also has a clutch spacer about 2mm thick. do some research and you will find it.

other options:
get thinner steels from rekluse. this is more expensive than using a complete cr250r clutch pack.

if you do convert to cr250r clutch, be nice and make sure you paint marker 'cr250r' inside the clutch cover so the next guy who owns your bike doesn't end up scratching his head when his brand new gg clutch pack won't work...

dragging clutch solutions:

lighter oil - i use amsoil 0w-40 and maxima mtl xl (75w) - both work nicely. i have been told fully synthetic atf is even more slippery, and may help dragging..but atf has no shock modifiers as far as i know...

lower your stack height - if you clutch stack is 29mm or more, it will drag - not enough free space when clutch is pulled. you can decrease your stack height by using thinner steels - rekluse sells them - it only takes .1 - .2mm less or so to go from dragging to slipping.... try one 1.4mm steel first and see if it works..

check your hub and basket for wear on the fingers/grooves. if there's wear you can draw file them smooth - this only works once or twice - after that too much material is gone and the clutch will chatter/break plates

check your steel plates - any warpage can cause drag.

Squealing/Chirping clutch


as shown elsewhere, there are at least 3-4 different baskets - http://www.gasgasrider.org/forum/showthread.php?t=8486

i found on my inner hub, that there were only 6 holes drilled in it. not 18 like the one pictured in link above. i drilled 12 additional holes, and my clutch is significantly smoother/easier to slip/and makes absolutely no noise.


other stuff:



make sure your cush drive inserts are not worn out, and no rivets are missing. there should be no play between the primary gear and the basket... i drilled my rivets out and tapped in new screws instead of rivets. i used grade 8 5x14 button head sockets, that i screwed in from the backside of the basket.. and at least blue loctite them....

if you are breaking clutch plates, there's a couple of possible reasons - jim senegal suggests using fsr450 springs (heavier). other reasons could be worn out friction 'fingers' leave much gap and hammer away at basket fingers, and using friction plates that have worn too thin.... if you break a plate, the plate pieces will migrate to the lowest spot in the case, which is under your shift selector scorpion - and you will not be able to shift down......

i'm sure there's more questions, but these are the ones i keep seeing come up..
 
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Nice work Stainless, that should cover a lot of questions.
Great write up.
Cheers
Mark
 
Do you think that these mods would allow for the the use of a Rekluse-Pro series clutch from a cr ?
 
i don't see why not. when you mill the thrust washer, it makes the clutch pack identical (aside from primary gear) to cr250r.. you may need 2 gaskets to clear the rekluse, but i'd think that would be it..

with the rekluse pack, you can use their thinner steels to achieve the same thing i believe - without needing to mill anything. you just need to loose about 1mm of total stack height from the cr250r clutch to work..... i've learned from playing with so many dry clutch ducs, which have many similar issues, that it's all about stack height...


if you can find the kawasaki or suzuki washer that fits, you would need to make no permanent mods to your thrust washer to try it out...i haven't checked the suzuki part number to see if it's correct.
 
on second thought i am not sure. i haven't investigated the clutch throwout bearing assembly on a cr250r. if they are similar it will work.... or you may need to get a gasgas throwout bearing spacer (if there is such a beast) from rekluse.
 
i don't see why not. when you mill the thrust washer, it makes the clutch pack identical (aside from primary gear) to cr250r.. you may need 2 gaskets to clear the rekluse, but i'd think that would be it..

with the rekluse pack, you can use their thinner steels to achieve the same thing i believe - without needing to mill anything. you just need to loose about 1mm of total stack height from the cr250r clutch to work..... i've learned from playing with so many dry clutch ducs, which have many similar issues, that it's all about stack height...


if you can find the kawasaki or suzuki washer that fits, you would need to make no permanent mods to your thrust washer to try it out...i haven't checked the suzuki part number to see if it's correct.


That's good info. I'm going to look into it.
 
Id be interested to hear how you go on this :D


I just recieved my bike late last week,11' 6 days 250. I'm still prepping the bike, regreasing everything and adding all the odds and ends to get the bike ready for the up coming racing season. After I get the jetting sorted out I'll try and look into this clutch conversion.
 
so that line of BS that rekluse used to explain why the only option is the 900 $ setup, is simply that, bullshit

I wish I had seen this sooner, I woulda just put in a dynaring or the cheaper rekluse EXP

this core exp setup changes the disk's and the throwout setup and puts in a new center, it's a pretty complicated setup compared to the dynaring or just an exp
 
Hey stainless I dont supose you know of a step by step to get to my basket to inspect these rivets? I have never had a clutch to pieces but im almost certain this is the problem with my bike.. I am planning on using m5 bolts like you have.. Do you have any photos or any more info would be extremely appreciated cheers.
luke
 
pm sent..


sources of rattles:

loose motor mounts (especially the top one) - this usually makes massive vibes when rev'd - not really a rattle. feels like your clutch is gonna explode - you can feel the centrifugal force of the motor when motor mounts are loose.

chain slap

pv not pre-loaded properly, so it rattles at low rpm's - kinda sounds like chain slap.
 
Thanks stainless I've had the power valve to bits with new bearings and a soak in an unltra sonic parts washer smoothe as a whistle now mounting bolts are torqued up correct top ends been re nikasil and new piston/rings it makes the noise like a ting/clang while reving low hopefully this will be the cause cheers luke
 
My 2011 was making an odd rattle on deceleration. I figured the top end was due or something. A new set of O-rings on the exhaust cured the rattle.
 
The powervalve is fine as far as I know.. what do you mean by pre load the actuator arm? The rattle has been there since before the top end rebuild
 
Ok.finally got time to fit the Tusk Honda CR250 clutch kit to my 07 300EC today. I used the Suzuki thrust washer behind the inner hub as well.The first thing I realised was that the steel plates would not go on the inner Hub :( WTF ! the splines have a slightly different angle, anyway No big deal, I then fitted the OEM steels with the Tusk fibres and put everything back together. As I am waiting on some new water pump parts I cant fire here up, but I checked the clutch actuation by turning the rear wheel in second and everything looks promising.Fully released the engine turns, about half way engaged the clutch was just starting to slip. so when it is back together I will let you all know he she goes. It has to be ready and right by the 25 of Feb as we have an Australian offroad championship round at Dungog (Forest 300) :)

Ollie
 
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