Clutch spacer?

the reply of my friend..

The shims between the spider and the moveable sheeve control the way the weights act. The less shims, make the weights feel heavier at low RPMs because it takes more pressure to get them to fling out which lets the motor rev up higher to get the weights out. More shims will make the weights feel lighter because the spider is already that much further away from the weights to let them have leverage against the spider to push easier. If the spider is too far away from the moveable sheeve the weights will not push as hard on the spider because they are already fully extended. Removing a shim will make the weights feel heavier throughout the entire RPM range. Also a lighter weight may need to be installed to keep engine performance at bottom end but the weight mass with a shim remove may be just what you need to get the belt to go all the way to the top of the clutch even with a lighter weight (maybe 1 gram or so). Excessive shims in the clutch will also tighten up the belt while the engine is idling or not running. This should not normally be a problem, you should really look at another model that you know has not been molested in any way. Check the belt clearance when the engine is not running at the clutch compare it to yours, compare the amount of shims and compare clutch weights. I purchased a clutch for my sled 5 years ago that did the same thing, had to change the shims because the belt wouldn't go all the way up and the clutch was supposed to be for my model. They have an interchange that says clutch-x, clutch-y, clutch-z can all be put on an engine but they don't tell you that modifications may be necessary, I just happened to get the wrong one once. Played hell trying to figure it out.

I am not going to go into this clutch shimming thing anymore I am a Polaris certified Tech and have been working on sleds for years now and if you want to take your freinds advice have at it but don't post that your sled hit a tree when you started it or that the pto end broke off your crank because your clutch is a piece.
It is plain and simple if the belt to sheave clearence is ok and the clutch closes all the way when you take the spring out then there is nothing wrong with the clutch.
Also have you had the crank checked to see if it out of index as this could also be a problem also are you sure the base timing is Correct as this could also cause problems.
As I have posted before this is not the same motor as all xlts and mill not put out the same as an older xlt sp or older reg xlt as the sp had 38s for carbs and the regular had 36s for carbs and yours has 34s for carbs Also the change to the evolved body required a pipe change and this also was known to take power from this motor. Everbody on this form and the other forms you have posted this problem on can give you good advice but you seem to think that your freind has better advice,So why do you even ask if you and your friend already have the answers.
........SNORAT......

Fortress !!! Listen to Snorat. He told you the correct answer about the shims. I also gave you that same answer on another forum. The amount of shims have very little to do with how the weights react. If you would actually look at a clutch you would see that the heel of the weights has a pin through it that fastens the weight to the moveable sheave. The surface of the weight pushes out against a roller that is mounted in the spider. In between the moveable sheave and spider is where the shims are. If you add shims then the distance between the clutch sheaves will decrease and thus the belt to sheave distance will decrease. That's the physical layout of the clutch. Pretty simple actually. The action of the weight itself is determined by the actual amount of weight and also the weight distribution due to its shape. The problem with getting too much advice is that sooner or later you're going to get a line of BS with it. Another word of advice is that you don't have to post your questions on every conceivable board you can think of. Most guys are on all the boards just as you are. Buy Olav Aaen's Clutch Tuning handbook and read it.

Here it is out of the POlaris manual.    

   Belt to sheave clearance should be as close to .020" as posible with out creating drag on the belt when positioned around the hub at the bottom of the sheaves.
 
   Add or remove spider washers as required t0 to achive desired belt to shean
ve clearence.

   For example: if belt to sheave clearence is .020" too large,removing one .020" shim will position the movable sheave closer to the fixed sheave reducing belt to sheave clearence by .020".

   This is typed right out of the Polaris snowmobile service manual Volume IV.
   
   Also states that any time shims sre added or removed that clutch should be reindext or clutch balance will be efected and cause engine damage.