I asked the dealer what the belt deflection should be, and he looked in the repair manual, and there was no belt adjustment spec. Someone else told me that 25-30mm is what it should be. You can't really adjust it, other than putting a new belt on.
The original belt had no ribs on the top. I think the ribs are for cooling. The original belts were recalled, which would make sense since the original belt was delaminating, probably due to heat. The dealer swapped belts with me and did all the recall paperwork, even though they haven't seen the quad.
I ordered and installed the white spring from EPI. The reason I got the white spring from EPI is that it will tighten up the belt. Loose belts wear faster. The white spring in the driven (rear) pulley will tighten it up, and cause minimal gear ratio changes (for the better). The 300 and 400 springs point outward on the end, and the ends fit into holes (not compatible with 360/650/700 springs). The holes are numbers 1 and 2 in the helix, and A B and C in the pulley sheave. A2 is the tightest for highest backshifting (big tires) and c1 is the lowest spring tension for smallest tires and lowest RPM's.
A loose belt makes the machine not take off as quick and not have as high of a top speed. There were two shims in between the pulleys on mine. I did not remove them since I felt the belt was pretty tight already. I wish I had removed them. You know what, I still can.
Belt Removal
1. Remove right floorboard. Remove foot brake lever. Disconnect the rear cvt vent hose from cvt cover (big air hose). Remove cvt cover.
2. While rotating driven pulley with hand, work belt over side of driven pulley.
Driven Pulley Removal
1. Remove belt.
2. Remove driven pulley bolt (lefty threads). Pulley slides off. I used a wrench, and I hit the wrench with a hammerin order use inertia to get the bolt loose, since I could not hold the pulley still. An air impact would work better, which I have but it was not with me at this time.
Driven Spring Removal
1. Remove belt.
2. Remove driven pulley.
3. using circlip remover, remove circlip while compressing the helix by hand (it's the aluminum hub you see around the circlip). It may come off anyway without pushing, but it may pop apart a little. Note which number the spring is in, you can see the end of it poking through hole 1 or 2.
3. Pull helix upward by hand, and pry it out gently if neccessary. Note which hole the spring was in, ABC, in the pulley sheave.
4. Clean stuff, put new spring in if you got the white one from EPI, or the old one back if you just wanted to alter it.
5. The spring needs to be preloaded during reassembly 1/3 of a turn. If you were just to squeeze it back together without preloading it, it wouldn't shift right. Do this by twisting the pulley sheave a full "tower" in order to work right. Tower refers to the points on the helix. There are 3 towers, so 1/3 of a turn will probably get you there. I think you turn the loose half of the driven pulley clockwise, but I can't see it now. The way you can double check this, is to look at which sides of the helix towers have wear, the spring should be forcing the pulley shoes to wear on that side of the towers. The top of the belt pull toward the front of the vehicle, and also pulls that half of the pulley onto the side of the helix that is worn. Good luck.
