The vibration you feel is probably a worn belt, so check you belt, run your fingers along the sides of the belt. You will probably feel a dip in the sides. If so toss it and get a new belt. If you don't it will hammer on the crank shaft and possibly snap it.
Life's Short Ride Hard!
Sled: 2006 Trail RMK 700
SLP Y-Pipe, Single Pipe, Silencer
SLP Velocity Stack
V-Force 3 Reeds
SLP Flow Rites (2.5")
5 3/4" Riser
Clutching:Primary Grn/Blk 10-62, Secondary Red/Blk 62-40-42/62-44-42 helix