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yfz450bb07
03-11-2009, 03:28 AM
What is the cause of the washer stacks to fade so bad?? We have had a couple of stacks fade pretty bad after just one ride. We have a 65 motor that is jetted good and a rider that does not blurp the throttle but is very aggressive in the corners and weighs about 60 pounds. thanks for any help..

THARNESS
03-11-2009, 07:32 AM
Heat seems to be the number one culprit. Heat builds when the clutch shoes are slipping. Be sure that your son is either on the gas or off (no blurping). Also be sure that your quad isn't geared too high. A couple of more teeth on the rear sprocket can make a big difference with the auto clutches. We also ran more clutch fluid than cobra suggested. If I remember right, cobra said to use 8oz and I always had better luck with 12oz.

It has been a couple of years since I had a auto Cobra , but I had the same issues back then and this is how we fixed ours. Good luck.

Ryko racing
03-11-2009, 08:34 AM
Heat will cause this.

We also ran a larger rear sprocket.( it is better to rev than to load the motor especially the 65 as it runs hot anyway)

We had trouble with the slipper clutch heating up also, the slipper is just a paper disc and a hard rider can cook one in 1 day.

Also we dump our fluid after every moto and replace it with
fresh fluid after every moto.

What radiator are you running???
What type of fluid???
How often do you change the fluid??


Let me know and i can probably help you as we went through it and finally figured it out

heathmxracing
03-11-2009, 09:22 AM
Well said guys. Just a few things to add.

Try restacking your clutch once you notice it fading. Just add a flat washer/shim that brings it back to where it was stock. Most guys change the clutch springs out quite frequently epically on the larger engines. One alternative is run a different style clutch. If you need some help let me know and I can give you more info.

Also, the new slippers use a carbon fiber disk on one side and a brass ring on the other. If you have the old paper style I would suggest upgrading.

yfz450bb07
03-11-2009, 09:50 AM
Thanks for the help guys. But I run about 10-11oz of fluid, change it after every ride and I am running the yfz450 radiator with a temp gage and it usually doesn't get over about 210 degrees. Oh ya I am running the Bud slipper. thanks..

Ryko racing
03-11-2009, 10:08 AM
call paul marra 609-387-3060. we tried a different set up and never had the issue again.

cobra11
04-12-2009, 08:47 AM
what kind of cluth fluid is best??? i use clutch milk something better??

THARNESS
04-13-2009, 09:14 AM
Clutch milk works good but can get pretty expensive. We used oriellys auto transmission fluid and changed it after every moto with good results.