Keep It Cool - Replacing the Water Pump Belt
A step-by-step how to of sled mechanics.
If you own a Polaris snowmobile based on the 700 or 800 "big block" motor, there is an important piece of maintenance you shouldn't overlook.
The water pump and oil pump on this motor are driven by a belt that runs off the crankshaft. Should this belt wear out and break you will be without a water pump or oil pump and heading for certain engine failure. Polaris specs that the water pump belt should be changed every 1500 miles. On most chassis this is fairly easy to do in an hour or so, but the exception to this is the Pro X models. Here, the motor must be pulled from the chassis in order to access the belt.
You can buy the water pump belts from Polaris but they come at a fairly hefty price, upwards of $50. For the last few years I've been buying mine from http://www.royaldistributing.com They ring in at $24 and they have worked perfectly.
The sled used in this example is a 2003 XC 700 which was selected because it will be very similar to most Polaris machines on the market where the water pump belt has to be changed.
First you remove the pipe and silencer so you can then access the pull start cover. This little job is made a lot easier by using a spring removal tool. They are not expensive and you will find that they are one of the best tools available for working on sleds.
Spring removal tool: no more skinned knuckles when using this.
Exhaust pipe and silencer removed: in order to access the water pump belt you will have to remove the pipe (resonator) and the canister (silencer)
Once you remove the pull start cover you will be able to access the water pump belt. Simply pull off the old one and put the new one on. You will notice that the new belt fits around the pulleys with no slack. If it does not then the belt may not be in spec and should be swapped for a different one. It's worth noting, however, that I have never had to do this and all the belts I have bought over the years have fit perfectly.
Pull start cover removed: Once the pull start cover is removed it's easy to slide off the old belt and slide on the new one.
Installation is the reverse of removal. I use blue Locktite on the pull start housing bolts so I know they won't come loose over time.
While I have my pipe and silencer out I take off the chaincase cover and clean it out. There is a small drain hole in the bottom of the belly pan that will allow the oil to flow out so make sure that you have something under the sled to catch it. Then I spray the inside of the chaincase down with brake cleaner to get all the sludge out of it and the wipe up the excess oil and brake cleaner. Reinstall the cover again using a small amount of blue Locktite on the bolts. Once that is all installed then and add the appropriate amount of gear oil. I typically use synthetic 75W90 gear oil that can be found at any auto parts store.
Inside chaincase: a lot of sludge can build up inside the chaincase and now is the perfect time to clean it out
Next install the silencer and then install the pipe using some flexible exhaust sealant to seal the pipe to the silencer. The sled should be left to sit overnight so the silicon can set up and create a good seal.