Arctic Cat 1000 TRV H2

A friend brought over an Arctic Cat 1000 TRV H2 with a broken drive belt.  This is Cat's big top of the line ATV, with a twin cylinder 1000 cc motor, two up seating and all the fancy extras.  He had already purchased a spare belt and I thought that it would be a quick easy job.

When I pulled the belt cover off and removed the debris from the old belt I found a small piece of plastic and a metal key for a shaft.  Obviously there was more trouble than just a broken belt.  I removed the secondary clutch and discovered that the helix was cracked.

This first photo shows the clutch on the work bench with an improvised setup to compress the spring.  I used a piece of all thread and a few metal scraps to compress the spring enough to remove the snap ring.

Here is the broken helix.  You can see that the part cracked right at the corner of the groove for the keyway.  This is a classic example of a failure at a stress concentration.

This machine has a powerful engine on a large and heavy chassis, I wonder if the Arctic Cat engineers did not design a drive system that is tough enough to handle it?