I have a 2002 Yamaha Grizzly automatic, It idles great but it goes into gear very hard and dies. Whats wrong??

Answer 1

They use a speed actuated clutch, belt and driven unit.
The clutch is stuck engaged, as opposed to fully retracted releasing the drive belt.

You may be able to get it to free-up if you raise the rear wheels off the ground and engage the transmission again.

Just a note*
Push the ATV up against something solid with the front bumper just in case the rearend falls onto the ground while it's engaged.

ADDED:
Make sure it's in two wheel drive when you do this. Not 4X4.

ADDED#2
Exclusive, fully automatic Ultramatic" transmission is the most advanced drive system in ATV-ing with excellent all-wheel engine braking.

Automatic centrifugal and one-way sprag clutch help ensure constant belt tension for superior no-slip performance and reduced belt wear.

Copied from:http://www.motorsports-network.com/yamaha/atv2002/grizzly.htm

Answer 2

Adjust the auto clutch.