Riding Mowers & Tractors: Why is my riding mower leaking oil or gas?

Check the oil level when the engine leaks oil. Drain oil to the full mark on the dipstick if you find the engine overfilled. A leaking head gasket or sump gasket can also cause oil leaks. Replace any damaged engine gaskets. If you notice gasoline stains on the pavement or garage floor, investigate the source of the leaking fuel. Rebuild or replace the carburetor if it leaks gas. Check the fuel pump for leaks and replace the pump if it's damaged.

riding mowers & tractors

THESE REPAIRS MAY HELP SOLVE YOUR RIDING MOWERS & TRACTORS PROBLEM

JC-RM-Replace-the-riding-mower-carburetor-assembly

Replace the riding mower carburetor assembly

The carburetor mixes gas with air before the fuel goes into the cylinder. If the gas/air mix isn't balanced, the engine won't start or the engine will run rough and stall when you try to drive the riding mower. A damaged carburetor may also leak gas. Replace the carburetor if it causes any of these symptoms.

Riding mower carburetor assembly

Find the required part specific to your product.

RG-RM-Replace-a-Riding-Mower-Carburetor-Intro-Image
January 1, 2015By Lyle Weischwill

How to replace a riding lawn mower carburetor

When a lawn tractor engine surges or is hard to start, the problem could be a clogged or damaged carburetor. This DIY repair guide and video show how you can replace the riding lawn mower carburetor yourself.

Repair difficulty
Time required
 45 minutes or less
JC-RM-Rebuild-the-riding-mower-engine-carburetor

Rebuild the riding mower engine carburetor

The carburetor mixes fuel with air to create a combustible mixture that enters the engine cylinder and ignites to drive the piston. Impurities in gasoline can clog the carburetor, preventing the engine from starting. Carburetor clogs can also cause the engine to run rough and the engine may stall when you try to drive the riding mower. Seals and gaskets in the carburetor eventually wear out and can leak gas. Use a carburetor rebuild kit to refurbish a clogged or leaking carburetor.

Rebuild the riding mower engine carburetor

Find the required part specific to your product.

RG-RM-Rebuild-a-Riding-Mower-Carburetor-Intro-Image
January 1, 2015By Lyle Weischwill

How to rebuild a riding lawn mower carburetor

Does your riding lawn mower engine run rough or misfire? The carburetor might be clogged or worn. This DIY repair guide and video show how to rebuild the carburetor in a riding lawn mower in about an hour.

Repair difficulty
Time required
 60 minutes or less
JC-RM-Replace-the-riding-mower-head-gasket

Replace the riding mower head gasket

If you notice an oil leak and your mower's engine can't reach normal operating speed or the mower struggles to climb a hill, the engine may have blown the head gasket. The head gasket seals the cylinder head to the top of the engine. Air leaking past a damaged head gasket reduces cylinder compression causing a loss of power. A blown head gasket leaks oil because the gasket doesn't seal the cylinder head mounting surfaces. Replace the head gasket if it leaks.

Riding mower head gasket

Find the required part specific to your product.

JC-RM-Replace-the-riding-mower-fuel-pump

Replace the riding mower fuel pump

The fuel pump moves fuel to the engine from the fuel tank on the riding mower or lawn tractor fuel tank. If the engine won't start or quits after starting, the fuel pump might not be working. A cracked fuel pump leaks gasoline. Replace the fuel pump if it leaks or doesn't pump fuel to the carburetor.

Riding mower fuel pump

Find the required part specific to your product.

Symptoms common to all riding mowers & tractors

Choose a symptom to see related riding mower and lawn tractor repairs.

Main causes: punctured tire or inner tube, leaky valve stem, damaged wheel rim
Main causes: worn or broken ground drive belt, bad seat switch, transaxle freewheel control engaged, transaxle failure, dirty carburetor
Main causes: shift lever needs adjustment, neutral control needs adjustment
Main causes: worn or broken blade belt, broken belt idler pulley, blade clutch cable failure, bad PTO switch, damaged mandrel pulleys
Main causes: damaged cutting blade, worn deck pulley, damaged mandrel pulley, loose fasteners on mower deck components
Main causes: engine overfilled with oil, leaky head gasket or sump gasket, damaged carburetor seals, cracked fuel pump, broken fuel line
Main causes: clogged carburetor, damaged flywheel key, dirty spark plug, stale fuel, improper valve lash, engine needs a tune up
Main causes: faulty battery, bad alternator
Main causes: unlevel mower deck, dull or damaged cutting blades, worn mandrel pulleys, bent mower deck, engine needs tune up

Repair guides common to all riding mowers & tractors

These step-by-step repair guides will help you safely fix what’s broken on your riding mower or lawn tractor.

January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower rear tire

Your mower can’t run on a damaged rear tire. Here’s how to install a new one.

Repair difficulty
Time required
 60 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower blade

If a blade on your mower is dull or bent, replace it following the steps in this repair guide.

Repair difficulty
Time required
 30 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower fuel filter

Help your mower run better by replacing the fuel filter during your riding mower's annual tune-up.

Repair difficulty
Time required
 15 minutes or less

Articles and videos common to all riding mowers & tractors

Use the advice and tips in these articles and videos to get the most out of your riding mower or lawn tractor.

August 6, 2020

How to remove a lawn mower blade using a removal tool

By Sears PartsDirect staff

Learn how a blade removal tool makes replacing the blade easier and safer

April 9, 2019

Riding mower parts and supplies to stock up on video

By Sears PartsDirect staff

Keep these 6 things on hand to keep the mower season running smoothly.

January 1, 1970

How to tell if a fuse is blown

By Lyle Weischwill

Learn how to tell whether a fuse is blown