Although older, Ariens mowers still uses a suspended mower deck and a drive belt system to output power from the mower for cutting grass. This is a system still in use on popular riding lawnmowers. The V-belt on the Ariens motor, made of rubber and metal, wears out over time. This allows the belt to slip on the pulleys. Belt slippage causes the mower blades to spin slower and it decreases the cutting efficiency of the mower. If you have noticed this, replace the belt to correct the problem.
Disengage the mower lever to apply slack to the mower belt.
Locate the three bolts that secure the belt fingers next to the pulleys on the mower deck. Loosen the bolts with a wrench and slide the belt fingers away from the pulleys. The fingers are essentially guards to keep the belt from falling off the pulleys.
Pull the belt off the three pulleys. If you are not sure if you can remember how to route the belts, make a diagram before you take the old belt off.
Place the new belt onto the pulley system.
Place a 1/16-inch feeler gauge against the belt and then slide the belt finger against the feeler gauge. Tighten the bolt for the belt finger with the wrench. Remove the feeler gauge.