CLUTCHING BASICS

The clutch system of your snowmobile does the most work yet is looked at as some magical object by many riders. The clutches transfer all power produced by the engine to the track. If more power is produced, the clutch system needs to be changed to maintain efficient power transfer. The clutches must keep the engine in its powerband regardless of terrain changes.  

The primary (engine) clutch is the most important; controlling engagement and engine RPM. The cam arms work against the primary spring to determine engagement speed and then must overcome the secondary clutch pressure to maintain engine RPM. All tuning is done by changing cam arm weight or spring rates for proper RPM.

The secondary clutch should have just enough pressure to prevent belt slippage and to backshift quickly. Other than faster or slower backshift, no huge performance gains will be found in the secondary but it must work in partnership with the primary.  

Racers have a box full of tuning parts for various conditions but this is not practical for real world snowmobilers. Factory setups are very generic and must work with many different riders. What is needed is a system that can be easily changed to match the rider and his sled.

Heavy Hitters, with their patented adjustability, meet this need by saving the cost of buying many different cam arms and grinding them to desired weight and shape. Heavy Hitters not only allow you to add or subtract weight, but more importantly put the weight in the proper position. You can set-up for trail, deep snow, drags, radar runs, sno-cross, or cross country racing with the same set of cam arms. Not only will one set work in these totally different conditions but you can change from one setup to the next in minutes.

Basic clutch tuning to match your style of riding can have a tremendous effect on the performance of your snowmobile (see Clutch Tuning Handbook for complete tuning info). You can have all the power in the world but if you can’t transfer it to the track, you are just spinning your crankshaft. Clutching is one of the few things that will not only give reliable performance gains but can extend the life of many components and increase your fuel mileage.

Clutching is a win/win proposal; reliable performance, longer belt life, less bushing/sheave wear, improved fuel economy, and best of all is still possible for the average, garage mechanic to do. A bit of time spent here reaps big rewards.

Submit your question here: SHOP TALK FORM