1971 Arctic Cat Panther 440A    

After years of being relatively problem free this sled stranded me two times and nearly a third time on the trails last winter. The first was a burned piston on the PTO side. Next it lost spark on one cylinder due to a faulty condenser. Then it became very difficult to start, which I believe is due to low compression. I'll need to pull the top end before the coming season and see if I can rectify that.

This sled just keeps on running flawlessly. By far the most dependable of my "fleet". The only problem I had this season was a broken rear spring on the skid frame. Oh yeah, there was one problem when I ran over a snow-covered something-or-other and bent up the right ski, but that was my fault.

The Salsbury 910 clutch works OK, but I want to do a little experimentation with arms and springs to get the RPM's up just a bit. I found a source for NOS arm and spring service kits. I plan on putting in the stock kits that came on the sled originally and then work from that known baseline to get it operating as I'd like.

I did experiment with the round shaft Cat clutch late last season. The engagement was too high, and RPM's were high throughout the operating range as well. Add to that the complexity and maintenance requirements, and I'm just not real happy with it. I got a used Salsbury 910 (original clutch that came with this machine) from Dan Tomlanovich. I plan to clean and refurbish it and install it for this season.

I pulled the engine and discovered damage to the chrome lining in both cylinders. Time for a major overhaul. I replaced both cylinders with NOS items, and put in new rings. I also replaced the PTO and mag side crank seals and the O rings on the center split seal.

Removing one set of three weights from the Duster clutch sure had the desired effect on performance! The first time I had the sled on a wide, flat, groomed trail, I cranked her up to where the engine was singing along at a good sustainable clip, but not maxed out. I was shocked when I looked down at the speedo and saw I was ripping along at 60 MPH! It had more to give (well, not a lot more) under these conditions, except the handling at anything faster would be a bit more exciting than I care to experience. I suspect I'd get maybe 70 per out of the old girl on a road. 

One side effect of squeezing the throttle to the bar at these speeds is a very noticeable odor that I believe is the clutch pucks beginning to melt. Backing off just a tad eliminates the odor immediately. I've read that the Duster is designed for engines up to 35 horsepower, and that's just what the 440 Kawi is rated at, so I think I'm right at the ragged edge. Could be time to experiment with the Cat clutch.