For almost ten years now, Yamaha snowmobiles have pretty much all been fitted with the hard and durable â€œ8DNâ€ drive belt. Performance tuners have found that while this drive belt is a fairly hard compound and seems to last forever, this firm nature also leads to a fair amount of slipping. And as you should be aware of, slipping creates heat, which is also lost acceleration. Bad deal.
Any way, the Yamaha mountain tuners at Hartman, Incorporated in Nampa, Idaho have long been recommending the use of the Dayco Ultimax 3 drive belt as a performance substitute, drive belt #138-4432-U3. This particular drive belt is made of a softer compound (more grip, less slip) and it is slightly longer, allowing you to set up the secondary to get the drive belt to the top of the sheaves, providing the full shift ratio and lowest possible start ratio (tougher to do with the shorter OE belt).
Hartman also believes the hard OE belts have been the cause of the sheave cracking they’ve seen on a number of Yamaha primary clutches, due to the heat generated from the hard belt slipping (and often sleds that are not properly calibrated for the operating conditions, also leading to an increase in belt slippage and heat generation).
Hartman has a truckload of these drive belts and sells them cheap – call them at 208-468-1073 or visit www.hartmaninc.com to get yours.