It can be annoying when your routine garden chores are piling up, and the lawnmower doesn’t move. Most problems lawnmower users face are related to the cutting operation and handling. If you face such issues with a Lawn-boy lawnmower, this article will try to help you troubleshoot and fix them.

Lawn-boy Lawnmower Cutting & Drive Problems: Troubleshooting with fixes

If your lawnmower’s cutting performance has dropped, you should start by inspecting the blades. Check for blunt edges, wear and tear, and misalignment along the shaft, all of which can lead to poor results when it comes to cutting. In addition, wear and tear of the drive belt affects power distribution and results in the lawnmower getting stuck/not moving forward.

So, if you’re a beginner or a seasoned user, this step-by-step guide will help keep your Lawn-boy lawnmower running smoothly for many years to come.

Lawn-boy Lawnmowers: Troubleshooting Cutting Problems

Inspecting and ensuring the proper functioning of mower blades and mowing deck is essential if you own a lawnmower. Failure to perform routine maintenance of the blade and its deck might cause cutting problems, such as those mentioned below. 

1. Lawn-Boy Lawnmower Doesn’t Cut Straight?

Straight-cust grass is important if you’re a garden lover or a professional gardener. If your lawnmower is not cutting straight, it could be due to the following reasons: 

– Unequal Tire Pressure: 

I recommend checking the tire pressure before any other component of the lawnmower fails to cut straight. Unequal tire pressure can cause the deck’s level to shift, resulting in some grass blades being cut unevenly than the rest.

Check the tire pressure with a tire gauge to confirm that all tires match the acceptable levels listed on the sidewall. Maintaining consistent tire pressure is needed for a smooth drive operation.

– Dull Blades: 

Cutting blades can get blunt over time, resulting in a worsening cutting performance. This is usually due to extensive use, severe wear from rugged terrain like sand or stones, or poor blade maintenance routine. Dull blades make mowing more challenging by decreasing the vacuum required for a clean cut. 

Regularly sharpening the blade edges with a bench grinder would be best. I recommend checking the blade’s sharpness before using your Lawn Boy Lawnmower. You can sharpen the blades without removing them, but I recommend removing them as this makes it much easier to check the balance.

– Unbalanced Blades: 

An imbalanced blade weighs more on one side than the other. This can occur due to irregular wear or blade damage. Also, excessive sharpening can result in metal unevenly removed from one side than the other. If a blade is dynamically unbalanced, it can vibrate excessively during rotation.

Excessive vibrations from unbalanced blades might lead to early degradation of the spindle bearings and a rough-cutting experience.

To check for blade imbalance, you can use a blade balancer tool. Or, you can hang the blade on a nail to ascertain which side is heavier and falls downward first. That side can be further sharpened until the blade is in balance.

However, particularly after more extensive blade damage, I recommend replacing the blade.

– Troubleshooting Spindle Bearings: 

If you hear squeaking noises while mowing and the grass is cut unevenly, there is most probably damage to the spindle bearings. To check the damage to the spindle bearing beneath the mowing deck, grab it from one end and move it back and forth. 

If you hear an audible knocking sound, it is undoubtedly a sign of a broken spindle bearing. If the bearing is faulty, replacing it is recommended. You can ask a mechanic for help to perform this replacement if needed.

2. Lawn-Boy Lawnmower Cuts Uneven Grass Patterns?

If a lawnmower cuts uneven patterns, it can be due to the following causes:

• Dull Blades:  If the blades’ edges seem rounded or blunt after inspection, consider sharpening them. If the wear and tear is significant, replacing the blades is recommended.
• Deck Height Adjustment: Make sure the deck is leveled at all four sides using adjustment screws. Follow the manufacturer’s recommendations to ensure the cutting height is set correctly. A level gauge can help make accurate changes to the deck’s height. 
• Drive Belt Maintenance:  Checking and replacing Deck Belts is essential in preventing uneven grass patterns. Worn-out deck belts might affect cutting uniformity and generate vibrations during mowing. Inspect the deck belts regularly for wear indications and replace them as needed.
• Inconsistent Mowing Speed:  Uneven grass patterns can be caused by fluctuations in mowing speeds. To obtain uniform and crisp grass edges, mow at a steady and level speed. Avoid rapid changes in cutting rate as it affects the cut quality.

3. Lawn-Boy Lawnmower Doesn’t Cut at All?

If your Lawn Boy Mover does not cut grass at all, follow the following steps to troubleshoot it:

1. Examine Blade Lever: 

The blade engagement lever must be activated to spin the blades. Examine the lever for any debris or grass clippings that might jam it and hinder correct engagement.

To guarantee smooth blade action, thoroughly clean the lower part of the mower deck and make sure all grass clippings are removed.

2. Inspecting the Blade Belt: 

A damaged blade belt might cause the blade to stop rotating. You must tilt the mower over and remove the mowing deck to access the blade belt.

Examine and replace the blade belt regularly if the teeth are worn or damaged.

3. Locked-Up Mandrel Assembly: 

The mandrel assembly contains the blade shaft and the bearings and is driven by the blade pulley. If the mandrel gets jammed due to debris buildup, the blades may not spin freely, affecting the cutting.

Misaligned bearings can also generate vibrations in the blade.

Tilt the mower over and remove the mowing deck to troubleshoot the mandrel. Remove the blade’s mounting bolts and the mandrel using a socket wrench.

You can purchase an identical one online by checking the part number or visiting your local dealer. Ask a professional for help if you are unsure how to fix the mandrel.

Lawn-boy Self-Propelled Lawnmowers: Troubleshooting Drive Problems

This section will discuss the most driving problems encountered with Lawn-boy self-propelled lawnmowers. Using the steps, you can troubleshoot and fix them:

1. Lawn-Boy Lawnmower Doesn’t Go Forward?

If your self-propelled lawnmower is unable to move despite the engine running, the following troubleshooting trips might help fix the problem:

a. Engage the Drive Control:

Start by checking the drive control lever or button’s position. Most users tend to ignore engaging the drive control lever, and the lawnmower doesn’t move.

b. Assess the Drive Belt: 

The drive belt drives the pulley, which engages the wheels. Inspect the belt by removing the mower deck and check the teeth for wear and tear. If the teeth are worn out, power transfer to the pulley would be reduced, and the lawnmower wouldn’t move.

Check if the belt is too loose. In that case, tightening can fix the issue. If the belt is damaged or worn, replace it.

c. Inspect the Wheels: 

If the problem persists, turn your attention to the wheels. Dirt and debris accumulated between the wheels and axle might hinder the wheels’ rotation.

I recommend removing all dirt and debris from your wheels and axle. Check that they are correctly mounted on the axle and can rotate freely.

2. Is the Lawn-Boy Lawnmower Throttle Not Working?

The throttle lever is used to control the engine RPMs and, in turn, the lawnmower speed. If throttle control doesn’t respond, try the following steps to resolve the problem:

a. Examine the Lever & Cable: 

First, check the lever to confirm it isn’t jammed. If it is difficult to move, use WD-40 or a lubricant to ease its movement. Do not forget to lubricate the cable as well.

Spray some WD-40 on the top or bottom, and move the cable ten times. That way, the lubricant can find its way to the whole cable.

Next, check if the cable gets tension when the lever is pressed. If the cable doesn’t move while the lever is used, the cable is likely to be broken.

b. Inspect the Carburetor: 

If the throttle lever moves correctly, but the engine doesn’t rev much or has a slow response, the carburetor might be the problem. Examine the carburetor jets for any old fuel residues. Use a reputable carburetor cleaner to clean the jets thoroughly.

Disassemble the carburetor, and clean the float bowl and bowl nut thoroughly. Test the throttle lever again after reassembly. In most cases, the problem should have been resolved. 

2. Lawn-Boy Lawnmower Vibrates Excessively?

Excessive vibrations are not only annoying but can cause damage to the spindle housing and the deck. The following factors produce vibrations:

a. Imbalance or Damage: 

Check for blade balance by holding the blade at its center. Unbalanced blades can cause vibrations throughout the mower at higher RPMs.

This problem can be solved by balancing or replacing the blade.

b. Loose Engine Mounts: 

Check for extreme engine vibrations that loose engine mounting bolts could cause. To prevent vibrations, ensure that all bolts are tightly secured, and none are missing.

c. Crankshaft Damage: 

Prolonged use under heat and excessive overrevving of the engine can result in crankshaft damage, which causes excessive vibrations.

This is an engine damage scenario, and this may require a new engine instead. I recommend asking a professional for help to determine if that is the case.

5. Lawn-Boy Lawnmower Is Leaking Oil?

A malfunctioning drain plug or a worn-out engine gasket is the most likely cause of an oil leak in your lawnmower.

A worn-out drain plug beneath the oil tank may also cause oil spillage. Avoid tilting the lawnmower with the air filter pointed downwards since this causes oil to flood into the combustion chamber from the crankcase.

Check the condition of the drain plug. Maybe it is loose or in bad condition. Keep the oil level at around 3/4 of the maximum to avoid overloading and subsequent leaks.

The second reason is more complex. Gaskets installed between the engine block and the cylinder head keep oil from entering the cylinder head. Gaskets can wear out due to thermal expansion, producing oil leaks over time.

Replacing the gaskets involves removing the cylinder head. This is a complex job. Ask a professional for help if you have never done this.

By following these troubleshooting tips and doing regular maintenance, you can easily maintain your lawnmower and enjoy a well-kept lawn. 

Drive & Cutting Troubleshooting table

1. Lawnmower Cutting Problems

2. Lawnmower Drive Problems

Riding Lawnmowers

Self-Propelled Lawnmowers