[Weldangrind]

Yozalo, it's not a good idea to ride the quad if the chain has no slack. As soon as the suspension is compressed, the chain will become even tighter. The chain will be ruined, along with both sprockets if it is used that way.

Imagine the rear axle moving up and down as you go over bumps. The axle isn't travelling in a straight line, but moving through an arc. If you compressed the rear shock enough that the front sprocket, swingarm pivot bolt and rear sprocket were in a straight line, that is where the chain may have no slack (but still not be tight). All other positions of the swingarm will be looser than that point of alignment.

If your chain is tight, you need to resolve it. The rear axle is attached to the swingarm with four bolts; two of them pivot and the other two are in slotted holes. Loosen all four bolts, back off the two chain adjusters and then the axle should move forward and produce chain slack. If the axle doesn't move forward, give it a few taps with a hammer and a block of wood. Once you get to the point where the chain is too loose, slowly tighten the two chain adjusters (evenly) until the chain has reasonable slack and then tighten the four axle mounting bolts.

Good luck.