I have a 2003 Ski-Doo MX Z REV 600 HO that I would like to make either a 136 or 144 with either an inch and three-quarter or a two-inch track. Can you give me any advice on clutching/gearing changes I might need to make for this scenario? Will this conversion lead to any cooling issues?
You will generally find lower gearing and more emphasis on backshifting when we add track length and lug height. The best starting point would be to look at how a Summit is clutched and geared compared to your existing calibration. You will, for the most part, be building a Summit or Renegade 600 H.O., depending on your track choice. Take a later year Renegade 136 with a 1.75â€ track and the 600 H.O. engine and youâ€™ve got your starting point if you go that length and height. Or, take a later year (so it is a REV chassis) Summit 600 H.O. with a 144â€ x 2â€ track and see what the clutching and gearing spec is. You might as well benefit from the time and effort the Ski-Doo staff spent finding the right set-up for a very similar machine, and go from there.
Or, you could reference the knowledge of a shop that does a lot of these kinds of conversions, like Specialty Sleds in Alberta (780-451-1130). They sell the (beaver tail-delete) kits and should also be able to steer you in the right direction.
Cooling problems? Logically, if you do not have the same total amount of extrusion surface area, there will be some extreme condition where your water temp will run higher than it would with more extrusion in the tunnel. This has usually only been an issue on ice and really low snow conditions. Yes, it will heat up easier, but it shouldnâ€™t be much of a problem if you ride it in â€œsnowâ€. Early morning crust could present a problem on select days, so pay attention. An actual temp gauge is always a good idea so you can see for yourself what the water temp is doing.