XS 650 Clutch Springs

PM clutch springs (the red ones), Cir Cycle, and stock Yamaha springs

Clutch spring free length measurements as stated in service manuals are only relevant to comparison check the length of the factory supplied stock springs to see if they are heat fatigued and have collapsed to less than their original length.

The springs on my Rimac spring tester above, left to right are:

Red = PM clutch springs

Blue = Cir Cycle

Unpainted = Factory Stock

I removed the blue springs from a 1980 XS 650 SG, the clutch was slipping. The drive plates (fiber .115") and clutch driven plates (metal .055") were perfect and measured at the stock thickness when checked with a micrometer. The problem was the longer than stock free length blue springs! The clutch spring installed height in the XS 650 is: .950" on the pre 1980 7 plate clutches and also on the later 6 plate clutches.

(Note: the XS650 fiber plates are the same dimensions as the stock fiber plates for a Suzuki GS 1000)

The blue springs at the installed height are: 38 pounds.

The *stock* springs at the installed height are: 55 pounds.

The red springs at the installed height are: 70 pounds.

The performance clutch springs above are from Precision Machining Inc. in Pacifica, Ca. They measure at 70 pounds at .950". They do not sell them anymore, I have 6 sets left.

Order them here: http://www.650motorcycles.com/PartsPricing.html

Return To:

XS 650 Yamaha Cycle Links, Images & Info: