One of the main parts of a riding lawn mower is the drive belt. Under certain circumstances, the belt may come loose or fall off. It is suggested that should this occur, the owner of the mower should perform a safety check. The check should occur after the mower has been turned off and the engine is cool. You should wear glove and goggles when performing the analysis and should also remove the spark plug wire or wires and ground it or them against the engine so the motor won’t accidentally start while you work.
Four problems could cause the drive belt to fail. They include:
• Problems with the mower mounting system
• A damaged belt
• Another damaged part
• Interference with the working of the belt due to debris.
If the mounting system for the drive belt is off balance, a number of problems could occur. Due to the imbalance, the mowing deck could be hanging and so the uneven deck could affect the belt’s operation. Moreover, it could cause the belt to come off. It is suggested that you examine whether or not the deck is mounted properly. Inspect for missing parts as well. Clip pines should be in place in the rear hangers and the draft rod should be correctly joining the mower’s front to the front axle. If things look okay, then the mower mounting system is not the issue.
Next to consider is a damaged belt. If a belt is damaged or loose it may come off the mower. Even if it doesn’t completely fall off, it can still cause damage. The belt may slip if loose causing friction that could create enough heat to result in a fire in the mower’s engine. If the belt is broken or worn, it can break when the engine is running and fly off the mower at a great speed, possibly causing injury to anyone nearby. Inspect the belt to determine if it is loose or if it is cracked, frayed or separated from the rest of the drive belt assembly. Should this be the case, replace it.
A number of other parts near the drive belt could be the culprits. Such things as the drive pulleys and idler pulleys can restrain the operation of the belt if they are not clean and in proper working order. Check to see that the arm moves properly and swings free without obstruction. Also be certain that the blade spindles turn freely. Check the mower’ rake or pitch. A correctly adjusted mower deck leans slightly forward causing the machine to be about 1/8th to ¼ of an inch lower in the front than in the back. If the angle is too great, the belt may come off.
A buildup of debris can also interfere with normal belt operation. Check to see if there is any debris caught on the belt. Debris lodging on a drive belt can cause it to slip or operate poorly and even cause a fire hazard. Remove debris with a clean cloth.
Replacing The Drive Belt On A Kubota Mower
If you discover that the drive belt of your Kubota mower needs to be replaced, it is suggested that you use a Kubota-made belt. This will assure a tight fit and optimum performance. The project will require you to remove the deck from underneath the mower, remove the old belt and install a new one around the pulleys in a suitable alignment.
You will need screwdrivers and a socket set to perform the task.
Here are step-by-step instructions on how to replace the drive belt.
1. Park the mower on a level surface, set the parking brake and remove the key from the ignition.
2. Disconnect the spark plug wire from the spark plug to assure that the mower will not accidentally start.
3. Adjust the mower to its lowest position.
4. Remove the four pins and washers that connect the lift linkage to the deck and keep nearby for re-installation.
5. Slide the mower deck out from beneath the mower. The belt is located in the deck.
6. Remove the screws that secure the belt guards in place and pull the belt guards from the mower deck.
7. Remove the screws that hold the belt keeper bar in play and lay nearby for re-installation.
8. Loosen the idler pulley nuts to release the tension on the pulleys. This makes it easier to remove the belt from the pulleys. Don’t remove the nuts and pulleys completely. Notice the routing of the belt before removing it.
9. Install the new belt on the mower and route it properly around the pulleys. If you are not sure of the proper route of the belt, consult your owner’s manual. There you will find a diagram that illustrates the proper routing. Take care not to twist the belt during installation.
10. Tighten the nuts that hold the idler pulleys in place to increase tension on the belt while you hold the pulleys securely in place.
11. Reinstall the bar keeper bar and the belt guards.
12. Slide the deck under the mower and reconnect the deck to the lift linkage with the pins and washers.
13. Adjust the deck lift lever to the appropriate height for mowing.
14. Reconnect the spark plug.
15. Start the mower and take a test run to ensure that the drive belt works properly.