You might think your snowmobile’s performance is at its peak.  It’s got great horsepower, the snowmobile suspension is perfect, and you’ve tuned the clutches just right.  Those clutches actually contain hidden horsepower, which will give your snow machine superior performance.

First, see how much clearance you have between the clutch sheaves and the drive belt.  If there is excess, it will reduce your acceleration and top speed.  This variance can be seen when two identical new sleds race and one is faster than the other.

In order to check your belt side clearance, slide the belt to one side of the clutch shaft.  Place a feeler gauge between the clutch sheave and the side of the belt.  Like the setting for your snowmobile suspension, look for the perfect range.  A clearance of .010” to .020” is ideal.

If your clearance doesn’t fall within this range, measure it again with a second drive belt that is new.  If your only issue is a worn drive belt, there is no need to toy around with the clutch.  If the measurement shows more than .020”  clearance, it needs some work.

In order to adjust the clearance, remove the spider and either add or subtract shims as you need to.  Check your dealer for more shims if you need them.  Special tools for clutch service and spider removal are also available, as well as those for snowmobile suspension.

Clutching system cleanliness is a second factor of snowmobile performance.  Clutch sheaves grab the belt when they are clean.  Material such as mold, oil, grease, gasoline, or even rubber build-up increase slippage and give you less power.

When cleaning clutches and belts, never use solvent-based cleaners like petroleum, alcohol, cleaning solvent, or other chemical-based products which cause even more slippage.  Instead, use steel wool to scrape off rubber buildup.  Wash the clutch faces with hot soapy water and wipe or air blow dry.

For particularly stubborn areas, use 180-grit sandpaper, being careful not to create low spots.  To remove contaminates, follow the same procedures listed above while using a medium to soft bristle brush.  The cleanliness of the clutch compartment is also important.