A smoking lawnmower can be alarming, but it’s often due to simple issues that can be resolved with basic checks and maintenance steps. Here are some common reasons your lawnmower might start smoking.

Overfilled Oil Reservoir

An overfilled oil reservoir can lead to white or blue smoke. It happens when too much oil is added, causing it to burn off during operation. To fix, check oil levels with the dipstick and drain the excess if needed.

Oil Spillage on Engine

White or blue smoke can also mean oil spilled on the engine. If you recently changed oil or tilted the mower, spilled oil might burn and cause smoke. Simply restart the mower to burn off the spill.

Using Incorrect Oil Grade

Using the wrong oil grade can cause white or blue smoke too. Verify that the oil matches the manufacturer’s recommendation. Look in your owner’s manual for the correct type of oil for your lawnmower.

Understanding Smoke Colors and Their Meanings

Understanding the color of smoke can help diagnose lawnmower issues effectively.

White or Blue Smoke: Oil Related Issues

White or blue smoke usually signals oil-related problems in your lawnmower. This could happen due to several reasons. If oil spills on the engine, for instance when changing oil or if the mower tips, the oil might burn off, resulting in white or blue smoke. Alternatively, an overfilled oil reservoir forces excess oil into the combustion chamber, leading to similar colored smoke. To resolve these issues, check the oil level using the dipstick and adjust as necessary. Ensure you use the correct oil grade as recommended by your mower’s manual to prevent this type of smoke.

Black Smoke: Fuel Mixture Problems

Black smoke indicates that your lawnmower is burning too much gasoline. This usually stems from fuel mixture issues where the carburetor isn’t mixing the correct amounts of air and gasoline. A common cause is a clogged or dirty air filter restricting airflow, resulting in a richer gasoline mix. Check and replace your mower’s air filter if needed. If black smoke persists, adjusting the carburetor may be necessary to ensure proper air intake. However, this fix might require professional help if you’re not familiar with carburetor adjustments.

Steps to Address a Smoking Lawnmower

Dealing with a smoking lawnmower can be straightforward with the right steps.

Checking and Changing the Oil

First, confirm oil levels using the dipstick. If overfilled, drain some oil until it’s right. Check for any oil spillage and run the mower to burn off excess. Always choose oil that fits the manufacturer’s recommendation.

Replacing the Air Filter

A clogged air filter could lead to black smoke. Replace it to restore proper air-to-fuel ratio. This is a simple step that often fixes the fuel mixture problem causing the smoke.

Adjusting or Cleaning the Carburetor

Finally, if black smoke persists, consider the carburetor. It may need adjustments or cleaning. For this, follow your owner’s manual or seek professional help if unsure.

When to Take Your Lawnmower for Professional Repair

Sometimes, home fixes might not solve the smoke issue. It’s best to know when to call in the experts.

Persistent Smoke Issues

If your lawnmower keeps smoking after basic troubleshooting, it may need a pro. Persistent white or blue smoke could mean oil leaks inside the engine. If black smoke remains after cleaning the air filter and adjusting the carburetor, the issue might be more complex. Professionals can diagnose and fix these problems safely.

Possible Air Leak or Worn-Out Components

A more serious issue could be an air leak in the crankshaft or worn engine parts. Continuing smoke of any color suggests these problems might be present. Instead of risky DIY fixes, take your lawnmower to a repair shop. Experts have the right tools to handle these situations.

Professional Repair vs. Warranty Service

Check if your lawnmower is still under warranty. Warranty might cover some repairs, potentially saving you money. If not under warranty, find a reputable repair shop. Always ask about repair costs before service to avoid surprises.

Preventive Measures to Avoid Future Smoking

To keep your lawnmower running smoothly and smoke-free, preventive maintenance is key. Here’s how to minimize the risk of your lawnmower smoking in the future.

Proper Maintenance Techniques

Regular Oil Changes: Change the oil as recommended by your mower’s manual. This prevents buildup that can lead to smoke.
Correct Oil Levels: Always check the oil level with the dipstick and ensure it’s at the suggested mark. Overfilling can cause smoking issues.
Clean Air Filters: Replace air filters regularly. A clean filter ensures the right mix of air and fuel.
Tune-ups: Have your mower serviced annually. Professionals can spot and fix potential problems early on.

Understanding Mower’s Inclination Limits

Read the Manual: Know your mower’s maximum safe tilting angle. Mowing on steep inclines can cause oil spills.
Use Caution: When mowing on slopes, do so carefully to prevent oil spillage onto the engine.

Routine Checks Before Use

Inspect for Leaks: Check for oil or fuel leaks before starting your mower. Leaks can lead to smoking.
Check Fuel Mix: Ensure you’re using the correct fuel type and mixture for your lawnmower.
Brief Inspection: Look over the mower for loose parts or damage that might affect its operation.

By following these preventive tips, you can avoid many common causes of lawnmower smoke and maintain your mower in top condition. Remember, regular checks and basic maintenance can prolong the life of your lawnmower and help keep it running efficiently.

Preventive Maintenance

Regular maintenance is key to keeping your lawnmower running smoothly and preventing smoking issues. Here are some tips:

Change the Oil Regularly: Change the oil and filter according to the manufacturer’s recommendations.
Clean the Air Filter: Clean or replace the air filter regularly.
Keep the Fuel Fresh: Store fuel in a clean, airtight container and use fuel stabilizer.
Inspect the Spark Plug: Check the spark plug for wear and fouling.
Store the Mower Properly: Store the mower in a clean, dry place during the off-season.

By following these tips, you can keep your lawnmower running smoothly and avoid the frustration of a smoking machine. Remember, if you’re unsure about any of these steps, it’s always best to consult a professional.

FAQs on Lawnmower Smoke Concerns

Low Oil Levels and White Smoke

Low oil can cause white smoke in lawnmowers. Check your lawn mower’s oil with the dipstick. If oil is low, add the recommended type until reaching the fill line. Always use the correct oil for your mower’s engine.

Dirty Air Filters and Black Smoke

Dirty air filters lead to black smoke from too much gasoline burning. Replace the air filter to fix this issue. Check the air filter condition regularly and change it when dirty.

The Significance of White Smoke

White smoke often points to oil problems. It could mean oil has spilled on the engine or the oil reservoir is overfull. Restart your mower to burn off excess oil. Check for correct oil levels and clean up spills.

Normal vs. Problematic Exhaust Smoke

A puff of white smoke at startup can be normal, but continuous white or blue smoke is not. Black smoke is always a problem sign. Continuous smoke of any color should be checked by a professional as soon as possible. Monitor your mower’s exhaust and act quickly on persistent smoke issues.

Common Reasons for Lawnmower Smoke