Kitty Cat Clutch Inspection

To verify a standard Kitty Cat clutch without taking it off the snowmobile, check at what rpm it starts to "tick the shoes against the drum". Clip a tachometer on the spark plug wire and a ground. Have the person slowly turn the throttle to hear at what rpm the shoes start to make contact to the drum. We tested 10 clutches to verify at what rpm the shoes start to tick against the drum. They start to "tick" from 1,800 rpm up to 2,100. Anything higher then 2,100 rpm, the clutch starts to lock up and moves the snowmobile forward. The SS1158LS clutch that we sell to Arctic Cat will engage to the drum prior to 2,200, if it doesn't then we would say the spring or the shoes have been altered for a higher engagement.

Remove the clutch from the snowmobile and take the drum off the shoe assembly by removing the outside snap ring. If you see that the inside portion of the drum that makes contact to the shoes is bare steel with no black oxide remaining then most likely the drum has been "trued up" which Max-Torque does but not to stock clutches. The Arctic Cat clutches are black oxide and have not been trued. A trued up clutch drum will measure 3.998 to 4.000 on the ID with a dial caliper. The trued up drum can be purchased from Max-Torque by a distributor or dealer but it is not a stock clutch drum for the Kitty Cat.

After you take the shoe assembly apart, verify the weight of the shoes. We spec out that the "SS" (six shoe) weigh 47 grams +/- 1 gram. Anything less then 45 grams would call for closer inspection. Yes, there will be some wear to the shoe but the drum would get fairly grooved before the shoe would show any wear.

Finally verify the spring length which we spec out at 9.050 to 9.150 and the wire diameter should be .054 +/- .001. This measurement is made on the outside of the two loops which is simple to do by placing the spring inside a 12" caliper. For the last four years, the springs we have provided to Arctic Cat have been painted blue for easier recognition. An older clutch used a plain (no paint) 302 stainless steel spring. Every spring is inspected prior to assembly to make sure it fits within those guide lines. The single digit number stamped on the back of the drive plate indicates the year we stamped the drive plate.

Max-Torque can inspect questionable clutches to verify if they have been altered. The only charge would be for the UPS back to the club. We would suggest that the tech people have several spare clutches on hand to swap out for the questionable clutch. The same day we get a clutch it would be sent back with a note by us saying it was stock and within our specs or it was altered.

James F Donovan
Vice President and Owner