Vortex ROK GP - terrible clutch squeal

Hoping somebody can help me - I’ve got an Intrepid Cruise MS3 with the Vortex ROK GP motor. At the end of the season, my clutch would make a nasty squeal as my kart rolled to a stop. I can get it to squeal when I have the kart on the stand and turn the rear axle with a bit of of speed.

A guy at the track indicated my clutch uses a bushing that needs to be lubricated. What do I lubercate it with?

Another guy said get rid of the bushing and go for a proper bearing.

I was looking through the ROK manual, and I beleive I have found the part requiring lubrication, and the replacement bearing.

Has anybody changed out the Z11 part with the Z12 or Z13 part? What is the difference between the Z12 and Z13 part?



The Z11.Z12.&Z13. in your pic. refer to the 11.12.&13 tooth sprockets. The 12&13 tooth use the needle roller bearing. The 11 tooth sprocket (which I assume you have fitted) uses the plain bush. See www.koene.com.
To lubricate the plain bush just run a few drops of engine oil between the clutch retaining washer and the sprocket using an oil can.


Is there any advantage to running the full needle bearing vs the bushing? I know the number of teeth on the engine sroket will change the gearing… but is the needle bearing better?


I don’t think there is any performance advantage. The bearing is only ’ operating’ when the clutch stops driving fully.
OTOH Vortex don’t use the plain bush on the 12t or13t sprocket.
If you can get suitable gearing you might consider a change to a 12t with the needle roller at some point and use a high temp. grease. Possibly longer ‘life’ with less/no ‘squeal’.

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