3 disc bully

R

racinnut15xm

Member
Bought a 3 disc bully has purple springs. only see red and black listed on bully website. Anyone know where these fall compared to those two? They are set in at .225 no bolts. Came off a world formula for a junior sprint going back on same. Didn't have a mychron on it but thing seemed to rev to the moon before engaging. Motor hasn't been dyno'd don't know max torque yet. Will get mychron on this week.
 
Purple springs are commonly used on modified/jackshaft clutches.

If you have a stock legal World Formula on your jr sprint, your engagement should be closer to 4000 rpm. That's one bolt in each lever with red springs @ .225."


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
CarlsonMotorsports said:
Purple springs are commonly used on modified/jackshaft clutches.

If you have a stock legal World Formula on your jr sprint, your engagement should be closer to 4000 rpm. That's one bolt in each lever with red springs @ .225."


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
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Far as i know its legal just picked it up Friday. Being we are racing this Friday where could i put bolts/installed height with the purples to get it close as possible? Air gap was close to .050 and had a huge stack of shims so i closed it up to .035 or so. It is on the jackshaft if that matters
 
The jack shaft typically reduces engine rpm down from 13,000 by 2.71.

So 4797 at the clutch on the jackshaft
For a Buller set up your may be different .
 
Most properly prepared Jr Sprints don't use a 21/57 Combo on the primary side like a kart would.

The latest setup from Buller uses Black springs at .225" with bolts in both holes.

They went away from Purple springs for Jr sprints about 3 or 4 years ago.

Getting to air gap down to around .030" should help if you only have purple springs.
 
Screenshot_20201102-211632_Samsung Internet.jpg
 
Michael Curry said:
Most properly prepared Jr Sprints don't use a 21/57 Combo on the primary side like a kart would.

The latest setup from Buller uses Black springs at .225" with bolts in both holes.

They went away from Purple springs for Jr sprints about 3 or 4 years ago.

Getting to air gap down to around .030" should help if you only have purple springs.
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Got a set of reds off an old single disc i could swap in but thats it.
 
Michael Curry said:
Most properly prepared Jr Sprints don't use a 21/57 Combo on the primary side like a kart would.

The latest setup from Buller uses Black springs at .225" with bolts in both holes.

They went away from Purple springs for Jr sprints about 3 or 4 years ago.

Getting to air gap down to around .030" should help if you only have purple springs.
Click to expand...
Why do these things need triple discs? I thought it was like 15hp per disc? I've talked to a couple people and they all run the triple.
 
Triple disc is preferred in my opinion due to the application -- high torque of the WF engine and heavier weight car. The ability of the extra plate and disc helps dissipate heat better too if you have an abundance of restarts.

If you're running the jackshaft, then follow what Mike said above....black springs, not red.
 
This class has been around a while.

The WF engine has been the engine mandated by the sanctioning body since they switched from the KT100 Yamaha.

The Bully Three disk is the prevalent clutch because it works.

If you are incapable of maintaining it, send it to someone who can. Don't jeopardize your racing program trying to save a few dollars.

That clutch is one of the most important parts of the equation.


And buy a few new belts......start the season off next year with a fresh one and change out on a regular basis, keeping the old ones as emergency backups.
 
i am capable and have the tools to maintain air gap, check disc thickness, and have the tool to set the spring height. Just no experience where to start and felt it was a good bit off. Everything looked to be in good shape when i closed up the air gap

I sent my single disc stuff to Carlson when i felt like it needed ground or deeper amounts of love.
 
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