Update: Nylon buttons have been added to the face of adjuster as shown above. The shim tool in video below is no longer required for belt changes.
Belt Adjusters have been around several years, but only for the SR Viper and Sidewinder. The Barn of Parts adjusters were designed so they will also fit most of the popular Japan built models such as Apex, Vector, Venture, RX-1 & FX Nytro. These adjusters will fit all 4 stroke models except the Phazer & Venture Lite.
Belt deflection is basically how tight or loose the belt is. A belt that is too tight will squeal when sitting still at an idle. A belt that is too loose will provide a more abrupt engagement and a sluggish take off as the drive ratio will be taller. When the belt is too loose the primary clutch has to slide in farther to take out the slack, and when it does this the belt is being driven on a larger diameter of the sheaves, which is essentially like pulling out in 2nd gear.
All Yamaha snowmobiles are provisioned from factory with means of adjusting belt deflection. On all secondary clutches except for the Sidewinder there are 3 small bolts on the back side of the secondary clutch with shim washers. These bolts and washers open or close the secondary clutch to adjust the belt deflection. Removing washers opens the secondary to loosen a tight belt, and adding washers closes the secondary to tighten the belt. This process works well, but it is not a convenient on the fly adjustment.
The Barn of Parts adjuster allows for quick and easy adjustments. The factory adjustment bolts and washers are completely removed and all the adjustment is handled by the adjuster. If a belt is too tight, you would simply just turn the adjuster clockwise to open the secondary clutch. If the belt is too loose you simply just turn the adjuster counter clockwise to close the secondary clutch.
As someone that always works on sleds belt changes are simple for me. There are however many out there that really don't understand the twist and push concept to open a secondary. There are also guys out there that know how to do it, but don't have the strength or mobility to overpower the spring force anymore. The adjusters also serve as a belt changing tool that opens the secondary clutch for easy trail side belt changes. When you insert the belt change shim tool you simply just turn the adjuster clockwise until the secondary is opened enough for you to slip the damaged belt off or new belt on.
The core of the adjuster and the mounting bolt are variables between the different sleds. I will also offer core kits, so in the future if you buy a new sled you can just purchase a core kit versus an entire new adjuster kit.
Complete adjuster kits will retail for $90. When you order in the online store, be sure to specify the correct model. Core kits will most likely retail for $35.