What spring height on new red spring off of clutch for a bulley clutch


6 brand new ones ...... .520. That is lightly taking the paint off of the coil ends with sandpaper on a granite base.


Premium User
Genuine Bully should take 1/2" springs (~.500".)
Make sure you don't use the clone/copy springs as they are considerably longer.
Also, don't just go by the spring relaxed oal. Check what they measure in a spring tester at installed height - that's what matters.
We go through a lot of effort/time to match springs on our Intercomp spring tester when we service clutches.

🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
Carlson Motorsports on Facebook
30 years of service to the karting industry
Linden, IN
They do things so much differently than I am used to from my 2 cycle days regarding 4 cycle clutches. The only time we ever measured spring height was when we 1st put the clutch together. Just a starting point! After that, we would adjust the clutch stall RPM, at the track, to the peak torque RPM (from dyno testing) of the engine. But that was the dark ages!