Weights get all the attention. Everybody swaps weights. But the spring on either end of a CVT is doing just as much work as the weights are, and it is the part most riders never touch — not because it does not matter, but because getting to it means splitting the clutch apart, and splitting a clutch apart looks like a good way to get hurt.
It is, if you do it with hand pressure and hope.
What Is Actually Stored in There
Take a secondary clutch. The spring inside is compressed and wound to a preload position, and it stays that way as long as the cover is bolted down. Depending on the machine and the spring rate, you are looking at hundreds of pounds of axial force plus torsional wind. It is not sitting still because it wants to — it is sitting still because a handful of fasteners are holding it.
Pull those fasteners without controlling the spring and the cover becomes a projectile. The primary is the same story: the cover is holding a compressed spring, and taking the bolts out in a criss-cross while leaning away from it is not a method, it is a gamble. Shops see the results. Broken fingers, a helix through drywall, and more than one set of clutch parts scattered across a shop floor because somebody figured it would only jump a little.
The Tuning Cost of Not Touching Springs
Safety aside, there is real performance sitting behind that cover. The primary spring sets your engagement RPM and, together with the weights, where the clutch holds RPM under load. The secondary spring — both its rate and which preload hole it is indexed to — controls how hard the belt is squeezed, how quickly the machine backshifts when you hit a hill, and how much the CVT resists upshift.
That is why two riders with identical weights can have completely different machines. If you have added tire, put a load in the bed, or moved from flat trail to steep two-track, the spring and preload combination is often the change that actually fixes the complaint — not another set of weights.
Do It With a Compressor
The Hunterworks Clutch Spring Compressor Tool takes the danger and the guesswork out of the job. It captures the clutch, takes the spring load off the cover fasteners in a controlled way, and lets you back the spring down slowly instead of releasing it all at once. Same tool, in reverse, to get it back together at the preload setting you actually want.
A few things that matter on a tool like this. It uses an ACME screw rather than a piece of threaded rod — ACME threads are designed to carry heavy axial load smoothly, where common threaded rod can bind, stretch, or strip at exactly the wrong moment. The handle is CNC machined one-piece steel, so there is no welded joint to be the weak point. It is powder coated, and it is made in the USA.
It works on both the primary and the secondary, which is the practical part — one tool covers the whole clutch job rather than two purchases. Fitment is broad: Polaris (all models), Can-Am (all models), and select Yamahas. Note that it does not work on the Yamaha RMAX, X2, or X4 — those machines take a different compressor.
A Sensible Order of Operations
Before you open anything, mark the clutch. A paint pen line across the cover, the sheave, and the housing lets you put everything back in the same clock position, which matters for balance. Photograph the preload hole the spring is indexed to before you change anything, because "I will remember" is how machines end up two holes off.
Then set the clutch in the compressor, take up the load, and remove the fasteners. Everything after that is ordinary shop work — clean the sheave faces, inspect the bushings, check the rollers or buttons while the thing is open, and only then change the spring. There is no sense compressing a clutch twice in one afternoon because you did not look at the wear items while you were in there.
The Part Worth Repeating
Springs are the cheapest meaningful tuning change on a CVT machine and the one most people skip. The reason they skip it is the tool. Buy the tool and the whole spring side of clutch tuning opens up — safely, repeatably, and on your own bench.