primary clutch shims question

[redbull660]

How much does one primary clutch shim increase the engagement one a yamaha clutch, I think its 200 rmps per shim. Does anyone know. thanks

 

[ak]

X2 and what is the part number for the shim? Is there a limit to how many you can install?

 

[Powderat]

Each shim is 200 rpms and I was told you can't use more than 2, because any more will cause your primary spring to coil bind.

 

[Frostbite]

I have been using spring shims for years. Yamaha recommends using no more than 3 shims. However, I used 5 shims last season without issues with an O/S/O on my RX-1M. I think I'm probably pushing my luck and three, maybe four should be the maximum amount of shims used at once.

I have been using them to increase the total force of the spring more than for engagement purposes. That way I can throw more weight at the primary clutch. Works for me.

Frosty

 

[Turk]

You can get away with more shims with a lower preload primary spring(under 35kg) but anything over that you have a lot better chance of coil binding by using more then 3.

 

[Frostbite]

Yup, that makes sense Turk.

The O/S/O is either a 30 or 35kg (I don't have the specs with me) so maybe that's why 5 shims has worked for me.

Shims can be a great tunning aid. They can raise your engagement and to a lesser degree raise your shift RPM. That's what I use them for the ability to load up my heavy hitters with just a little more tip weight.

Frosty

 

[ak]

Part Number ?

 

[snowdad4]

pt #: 90201-483p9-00

 

[ak]

^ thanks.

 

[ak]

Are you guys installing the shims below the spring are above the spring, Are does it make any difference.

 

[snowdad4]

i go under spring, clutch side, just for ease of cover installation.