View Full Version : Clutching 900 Fusion How to Explanation

09-15-2009, 09:29 AM
OK, so i keep reading from all the experts here about what i should do to my 2009 900 Fusion and what i should set the clutch at to make this sled really an animal. Well, thats fine and all, but i dont know what any of it means and i would like to know what i am actually doing before i do it, can anyone help me understand:

What does the clutch actually do?
What is the primary clutch? What is the secondary clutch?
What do the different colored springs do for primary/secondary?
What does the "gearing mean"? Top tooth? Lower versus higher gearing?
What is a helix and what does it do?
What are the different gram weights you are talking about? Why would i use some over the other weights?
What does "shift out" mean? Why is it important that my secondary is shifting out all the way, and how would i check or know that answer?

Thanks in advance!

09-15-2009, 09:51 AM
Here is a website that will give you some of the basics.


09-15-2009, 02:17 PM
the primary clutch is the front clutch thats on the engine,,,secondary is the rear (larger) clutch on the jack shaft...

different colored springs have different spring pressures,,, you have a opening pressure and a collapsing pressure,,,hence the two numbers...

gearing is in the chain case (opposite side of the driven clutch) top gear,, lowering one tooth will create more torque..raising one tooth will create more top speed...

bottom gear in the chain case,,, lowering a tooth will create more top speed,,, raising a tooth will create more torque...

all sleds are geared from the factory 1-2 teeth higher so the average joe can hold the sled wide open and never blow it up...

helix is in the driven clutch (rear larger one)the helix consists of 3 angled ramps wich the sheeve of the driven clutch rides on...the numbers on the helix signifies the ramp angle... most have two numbers,,, this means there are 2 slightly different angles in the ramp.. one more aggresive than the other... some have one number wich is a constant angle ramp...

wieghts are important for matching to the springs used.. also a higher hp engine will sling a heavier set,,the heavier the weight used the faster the primary clutch will snap closed...you have to find a happy medium with the springs ramps..

shifting out would be making sure the driven clutch is opening fully and the belt is going all the way to the bottom... same with the primary but opposite,,, you want to make sure the belt is riding up just about all the way to the top of the sheaves... take a black magic marker and draw a line on the inside sheave from about 3/4 all the way to the top... run the sled and you will see how high the belt rides.<font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font> will wear the marker off to a certain point.<font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font><font color="ff0000">•</font> should ride up pretty high 1/8&#34; or so from the top of the sheaves...

shifting out completely is very important for top speed.. if the clutches dont shift out all the way,,,the sled isnt as fast as it could be...

hope this helps you some...