A Spartan zero turn mower won’t move forward or reverse due to the drive release levers not being in the operating position, a worn hydraulic pump belt, a bad tensioner pulley, a missing idler arm spring, low hydraulic oil level, hot hydraulic oil, or air in the hydraulic system.

Take safety precautions when working with your mower’s hydraulic system. Remove the spark plug wire and ignition key prior to performing any repairs or maintenance.

Wait for the transmission to cool and take caution working with hot hydraulic fluid. Follow all safety precautions listed in the Spartan operator’s manual.

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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing, or operating.Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

7 Reasons a Spartan Lawn Mower Won’t Move Forward or Reverse

Spartan Zero Turn Drive Release Levers Not in the Operating Position

If you had to push your mower for any reason, you would have had to disengage the hydro levers so the mower will free-roll. Being able to free-roll the mower is helpful when it quits in the middle of your yard and you need to push it onto a trailer or back to the garage.

If you forgot to re-engage the levers, your mower will not move using the driving arms if the levers are not in the “operating” position.

A Spartan zero turn won’t move when the hydro levers are not engaged to power the wheels. You will find these hydrostatic neutral levers located on the Parker wheel motors near the rear wheels.

You will find two wheel motors – one for the left-hand side and one for the right-hand side. Look for the levers on the wheel motors to make sure they are engaged and pointed to the right (as if you were sitting on the seat of the mower).

If they are not, push the levers to the right so you can drive the mower forward and reverse.

Spartan Zero Turn Pump Drive Belt is Worn, Loose or Broke

A worn drive belt can affect the movement of your zero turn. Check the Spartan drive belt to make sure it hasn’t fallen off and is positioned correctly on the pulleys.

If the belt shows any signs of wearing, the belt should be replaced.

Spartan Zero Turn Tensioner Pulley is Bad

The bearing in the tensioner pulley or the pulley itself can break. Most tensioner pulleys are made of hard plastic which can wear over time or break.

Replace a pulley that is worn or has a bad bearing. Keep the tensioner arm greased so it does not seize.

Missing Idler Arm Spring on a Spartan Zero Turn Mower

The idler spring places tension on the pump drive belt. Replace the spring if it is broken or has fallen out of your mower.

Low Hydraulic Fluid Level in Your Spartan Zero Turn Mower

Consistent hydraulic fluid changes must be completed to keep your Spartan transmission system running at its best. Running the transmission with old or low hydraulic fluid can cause your mower not to move or seem very weak while running.

Always check the hydraulic fluid level before using the mower while the oil is cool. Always wipe around the caps before removing them to check the fluid. Dirt is often a factor in a failed hydraulic system so you want to take all precautions to not contaminate the system.

When your hydraulic oil is low, add more hydraulic fluid until the fluid level reaches the full level on the dipsticks or overflow tanks (depending on your specific Spartan model).

The hydraulic fluid in a Spartan zero turn must be changed at regular intervals to keep the hydraulic system operating at its best.

Use Parket HT-1000 transmission oil and change the oil and filters after the first 250 hours. The following oil and filter changes must be done at 1000-hour intervals.

It’s also a good idea to check for hydraulic fluid leaks when you find your hydraulic oil level is low. Contact your Spartan zero-turn mower dealership for assistance with hydraulic fluid leaks.

Hot Hydraulic Fluid in Your Spartan Zero Turn Mower

When you operate a zero turn with bad hydraulic fluid or low fluid, the oil is not able to efficiently lubricate the hydraulic system causing increased friction and overheating of the hydraulic fluid.

Hot hydraulic fluid in your Spartan mower can also be the result of more extensive damage.

I highly recommend taking your lawn mower to your local Spartan dealership if you experience leaking from the hydraulic pump or your mower runs fine when it is cold, but stops running when it gets hot.

Air in the Hydraulic System of Your Spartan Zero Turn Mower

Air trapped in the hydraulic system can cause your Spartan zero turn to move slowly or not move at all. After changing the hydraulic fluid, you must bleed the air out of the system.

On most zero turns, air can be removed from the hydraulic system by raising the rear drive tires off the ground.

With your zero-turn running, move the drive levers forward and then reverse to allow the tires to rotate forward and backward. Repeat until you don’t hear excessive noise and the tires move at normal speeds.

It is important to refer to your operator’s manual for correct procedures to remove air from your model’s hydraulic system.