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175 Posts
Discussion Starter · #1 ·
I have my secondary clutch apart to clean and inspect bushings,etc. I was wondering what I may expect to gain if I were to change the helix from the straight 50 to a 54-52-50?I have a new one on hand. Would the spring need to be tightened up some or left as is? Thanks for the help. The sled is a 500 mxz.

603 Posts
Stay away from step helix. When button goes thru transition area from one angle to the next as the sled is being loaded....the rpms become unstable.
Find a smooth progressive helix.

MHO...54 is much too large with only 4 degree spread. With the large angle helix you mention, you do not have enough force from the secondary spring to assist the helix to squeeze the belt.

Before you change your 50 helix....When you go out again and do some trial runs with it first...Be a little bit harder on the sled than you usually care to be.
Get on the fuel....get off...back on again and work the sled.
How long you performed this trial run??? 1 minute? 3 minutes? 6 minutes?
Stop the sled, pop hood and stick your hand IN the secondary clutch.

****Put the palm of your hand right on the sheave face that the belt touches and count how long you can hold your hand on it. count the seconds and try to be accurate.****

What is the primary sheave temp to touch?

You would also like to see the trial performed if you can go and run the sled at flat out speeds. Record how fast you went.
Grab the brake real hard...pop hood measure sheave face temp.

I beg you to use a notepad/pen[cil] when you make your measurement/comments.
You will find that you may take more data than you want....which is good.

The secondary sheave temperature will tell you a story.
Sheaves hot?...then belt is slipping between sheaves.
Sheaves cooler with cam change...Then belt is being gripped better in sheaves.

Try and find someone or ask around if you can borrow a:
50-44, 50-42, 50-40.

With the rest of the system being in stock configuration and you try these cams...You may find the rpms climbing a little. If so, do not change the clicker...rather instead add a setscrew to the TRA primary arms to get the rpms down.

...Watch the clutch temps go down...feel the increased responce to your throttle.
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