MTD: For a Growing World.
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General Riding Lawn Mower Maintenance

Length of Clip:  5:29

Depending on your model, the instructions below for a mower tune-up might vary slightly. If there are any safety features missing or broken, immediately take your riding mower to an Authorized Service Center or call to schedule a pick-up. For more detailed instructions please see our video and how-to libraries, which focus on the maintenance items discussed in this video. As you work, always observe the safety rules called out in your Operator's Manual.  Also, take note of any riding mower parts that need to be replaced.

Step 1: Position your mower for a safe tune-up

To begin, roll your riding mower onto a flat level surface.

Step 2: Disconnect the spark plug

Disconnect the spark plug wire(s). This is typically located under the hood, or behind the seat.

Step 3: Examine the spark plug

The spark plug(s) should be replaced every 100 hours or prior to storing in the fall.  Damaged or worn plugs can increase carbon build-up while decreasing fuel efficiency and power output.  Pay special attention to the numbers on the old plug. Make sure you buy a replacement plug with the same numbers.  Using a spark plug with the wrong specifications can be fatal to your engine.

Step 4: Treat the fuel in your riding mower

Difficulty starting the engine is the most common problem people experience with their mowers.  This problem is caused by bad fuel.  With today's emissions standards, small, air-cooled engines cannot tolerate un-treated fuel that has been sitting in a gas can for over 30 days, or fuel with more than 10% ethanol.  To prevent these problems, add a fuel stabilizer to your gas can every time you refill it.  Fuel stabilizers help to keep fuel combustibility levels up to specifications.  Untreated fuel can become difficult to burn in small engines in as little as 30 days.

Step 5: Change the oil during your riding lawn mower maintenance

Your engine's oil should be changed every 50 hours and prior to storing in the fall.  It is important to change your engine oil because heat and friction begin to break down the oils' ability to lubricate moving parts.  Additionally, the oil suspends and removes worn particles from the engine.  If left unchecked, these particles could cause premature engine wear.  It is also important to change the oil filter, as it helps to remove worn particles and dirt from your engine's lubrication system.  To drain the oil, use whatever method works best for you; many riding mowers have a drain plug that can be drained with the use of a plastic drain sleeve.  The easiest way to drain oil from a riding mower is to use the Arnold Siphon Pump.

Step 6: Fill the oil to the proper level

Refer to your Operator's Manual and or Engine Owner's Manual for the type and amount of oil needed to refill.  Do not overfill; it can be as harmful as under-filling.

Step 7: Examine and replace the air filter if necessary

The air filter should be checked every 25 hours and replaced after every 100 hours of use and prior to storing in the fall.  Dispose of the dirty air filter and install a new air filter.  If your mower is equipped with a pre-filter, you can clean it with liquid detergent and water, then thoroughly dry.  Never operate your mower without a proper fitting filter.  Dirt or grass can then accumulate in the engine, robbing it of power and causing abnormal fuel use.

Step 8: Sharpen or replace blades with new riding mower parts

Mowing with dull or worn blades is harmful to your lawn.  They tear, not cut, the blades of grass, making them susceptible to disease and browning.  If the blade is chipped, bent, or damaged, install replacement mower blade.  Running a mower with a bent blade can cause excess vibration and unsafe mowing conditions.

Step 9: Inspect mower belts

Remove the belt guards and check the mower belts.  If they are worn or damaged - replace them.  Refer to your owner's manual for the correct part number.  Remember to only use Genuine Factory Belts. They are designed specifically for your mowers pulley system and torque needs.  Non-original belts look similar, but may not set in the pulley properly or they may stretch, causing premature wear and replacement. Most riders also use belts to drive their transmissions. These belts can be challenging to service, so they are best maintained and replaced by a dealer. Loss of movement or sporadic movement could be signs of transmission belt wear or damage.

Step 10: Clean out the discharge chute and look for signs of damage

Check the discharge chute for damage. If this or any other safety feature is not functioning properly, immediately take your riding mower to an authorized service center. At this time, it's also a good opportunity to clean any debris build-up.  A putty knife works well for this.

Step 11: Look at the bagger on your riding mower

If your rider is equipped with a bagger, check all the chutes and bags for holes, damage, or tears.  Any of these could lead to an unsafe operating condition.

Step 12: Don't forget to look at the tires

Check your front and back tires and deck wheels for excessive wear or damage.  Replace if necessary.

Step 13: Clean up

At this point you have thoroughly maintained your mower.  Once all of the riding mower parts have been replaced, check to make sure all fasteners are tight.  Wipe up any fuel or oil spilled during the repair, and reconnect the spark plug wire.


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