2003 Polaris Deep Snow Snowmobiles Service Manual, Page 53Get this manual
MAINTENANCE Exhaust System
At approximately 1000 to 2000 miles, or in preparation of off season storage, it is good idea to check the exhaust system for wear or damageTo inspect, allow the engine and exhaust system to cool completelyOpen the hood and inspect the muffler and pipes for cracks or damageCheck for weak or missing retaining springs or damper support grommetsWARNING
Exhaust system temperatures can exceed 932 (500 C)Serious burns may occur if this inspection is performed without allowing adequate time for the exhaust system to coolNever perform this procedure with the engine running
Variable Exhaust System (V.E.S
Some snowmobiles are equipped with the Polaris Variable Exhaust System (V.E.S This unique exhaust valve management system changes the effective exhaust port height in the cylinder to provide maximum horsepower at high RPM without sacrificing fuel economy and engine torque at low to midrange throttle settingsSpring Cover