The Lawn Bug, more commonly known as the Yard Bug, is a riding mower manufactured by outdoor power equipment company MTD. Though MTD no longer produces Yard Bugs, you can still find replacement parts for the machines, so if your old Yard Bug stops running, you don’t necessarily have to buy a new mower. If the drive belt on your Yard Bug becomes frayed or breaks, for instance, you can simply replace the belt.
Get at the Bottom of the Unit
Before you can replace a Yard Bug belt, you must get to the belt. First, use the Yard Bug lever to lower the mower deck to the lowest position. Then, place a soft tarp or blanket over the floor next to the mower, and get help to flip the mower carefully over onto its side, so that the bottom of the unit is visible.
Get the Pulley Out of the Way
The mower deck is in the way when you want to remove the drive belt on a Yard Bug. Unscrew the bolt that holds the pulley on the bottom of the Yard Bug in place with a 5/8-inch socket wrench and pull off the pulley lever. Remove the metal pieces that hold the mower deck against the unit and pull the mower deck away from the unit as far as possible.
Get the Belt Off
Reach inside the mower deck carefully and remove the first belt that you see, which is the deck belt. Set the belt aside somewhere safe if it doesn’t also need changing. Pull the belt that lies deeper in the mower out of the unit. Pay attention to the way the belt sits on the axle and pulley shafts, so you can return it in the same way.
Get the New Belt in Place
Once you remove the old belt, it's time to replace the worn-out belt with a new one. Slide one end of the new drive belt onto the axle of the mower and the other end around the pulley, sliding it up into the position from which you took the damaged belt. Slide the deck belt back onto the axle and pulley in the same position that it was in originally.
Get the Mower Back into Circulation
After you have the belts in place, you must get the mower ready to run. Press the mower deck back against the unit and lock the metal pieces that hold the deck back into place. Hold the pulley back up against the pulley shaft and secure it to the shaft with the bolt. Last but not least, flip the unit back upright. Take the Yard Bug on a test run to make sure it runs properly before attempting to mow.