Normally, pop the coolant cap and disconnect a lower hose to the heat exchangers and most all will drain out. To purge, potentially, you could hook a garden hose to either end of open the coolant hose.
When filling, reconnect the hose, fill with at least a 50/50 solution, run it a bit on stand or idle with the coolant cap off or real loose to purge air, fill overflow as needed to balance system. Some sleds have an air purge fitting somewhere high on a coolant line or on the water pump. If so, loosen very slowly at idle until fluid comes out to purge the air bubble in your system. Of course, follow the manual specifics if available.
I usually take a small squirt bottle of 50/50 on my next trip in case I need to top off the overflow tank. I did it three times this winter working on chaincase problems. [B)]
A forum community dedicated to snowmobile owners and enthusiasts. Come join the discussion about performance, racing, troubleshooting, trails, maintenance, riding tips, modifications, classifieds, gear, and more!