As the owner of Straightline Performance in Forest Lake, Minnesota, Jason Houle and his team produce parts big and small to create more horsepower and get more of that horsepower to the ground. In doing so, Jason deals with a lot of people who think they might be great tuners or backyard mechanics. In actuality, some of those people miss some of the details. We asked Jason to tell us the five most common mistakes that he’s seen made by amateur tuners.
1. Belt Deflection Is Too Loose — Just because the belt sticks out of the secondary clutch a little bit does not necessarily mean that the tension is correct. The most accurate way to check belt deflection is to push against the belt with a finger midway between the two clutches and measure how far the belt moves. Pressure and deflection varies by make and model.
2. Track Is Too Loose — The adage of a loose track equating to a fast snowmobile is incorrect. Today’s machines require more tension as the ballooning effect at high speeds will cause the snowmobile to stop gaining speed sooner.
3. Didn’t Check The Basics — Bearings, bushings and alignment are seemingly minor factors that can, in fact, cause major performance losses.
4. Forgetting About Traction — Adding more horsepower will typically cause the track to spin more and lose acceleration. If you add performance products for the trail and expect to see gains in speed, traction accessories are necessary.
5. More Flyweight Mass Reduces Engine Speed — This statement may be correct, but not always. Today’s twin-cylinder engines have larger torque bands and might require several calibration changes in order to see the engine speed change. For example, if you add more weight and peak RPM stays the same, add more until it starts to lose engine speed. On the flip side, if removing weight does not cause the RPM to raise, the engine package might not have the capability to rev higher.