07/05/2017
A well-maintained lawnmower isn't just about prolonging its life; it's about ensuring your garden always looks its absolute best. Regular servicing keeps your machine running at its optimum performance level, significantly reduces the risk of mechanical breakdown, and, for many, even helps maintain warranty validity. As Adam Woolcott, a celebrated professional gardener with decades of experience, rightly points out, a little attention now can save a lot of frustration later. This comprehensive guide will walk you through the essential steps of a DIY lawnmower service, ensuring your trusted machine is always ready for action.
- Why Regular Lawnmower Servicing is Crucial
- Essential Pre-Service Checks and Preparations
- Engine Component Maintenance: The Heart of Your Mower
- The Most Critical Step: Lawnmower Oil Change
- Blade and Deck Maintenance for a Perfect Cut
- Other Important Checks for Overall Health
- Comprehensive Lawnmower Service Checklist
- Frequently Asked Questions About Lawnmower Servicing
- Conclusion
Why Regular Lawnmower Servicing is Crucial
Before diving into the practical steps, let's briefly reiterate why committing to a regular service schedule for your lawnmower is so vital. Beyond the obvious benefit of a healthy, vibrant lawn, routine maintenance directly impacts the longevity and efficiency of your equipment. Neglecting your mower can lead to decreased cutting performance, increased fuel consumption, and, most critically, costly repairs. Think of it as an MOT for your garden machinery – preventative care is always better than a cure. For many modern mowers, particularly those from reputable brands like Webb, adhering to a service schedule, often including an annual check-up by a certified dealer, is also key to keeping your manufacturer's warranty valid. Ultimately, a well-serviced mower means more enjoyable, hassle-free gardening for you.
Essential Pre-Service Checks and Preparations
Before you even think about getting your hands dirty, a few preliminary checks and safety measures are paramount. Always wear appropriate personal protective equipment, including sturdy gloves. It’s also wise to have a clean, flat workspace ready with good lighting.
Securing Nuts and Bolts
Lawnmowers, by their very nature, vibrate considerably during use. This constant motion can cause nuts and bolts to loosen over time, or even fall off. As your very first step, give your entire mower a thorough visual inspection. Gently try to tighten any visible nuts and bolts. Pay particular attention to the handle, wheel mounts, and engine housing. Ensuring all fixings and fastenings are secure is a quick and easy way to prevent potential issues and maintain the structural integrity of your machine.
Inspecting the Pull Cord
The pull cord is your direct link to starting the engine, and a worn one can quickly turn a simple task into a frustrating ordeal. Gently pull the cord all the way out, inspecting it for any signs of fraying or wear, particularly at either end where it attaches to the handle or the engine. If the cord looks tired, or if you spot any significant fraying, it’s best to replace it. While a pull cord snapping mid-start is a rare occurrence, it’s an inconvenience you’ll want to avoid. Replacing it proactively is a simple task that saves time and frustration down the line.
Engine Component Maintenance: The Heart of Your Mower
The engine is the powerhouse of your lawnmower, and several key components within it require regular attention to ensure efficient operation. Always remember to disconnect the spark plug lead before working on any part of the engine to prevent accidental starting.
Replacing the Spark Plug
The spark plug is often overlooked but plays a crucial role in your mower's starting ability and overall performance. Its condition can tell you a lot about your engine. To access it, you’ll typically find it at the front of the mower, covered by an HT cap. Simply pull off this cap to expose the plug.
Once the cap is removed, it’s absolutely essential to remove the spark plug itself before proceeding with any further inspection or maintenance of the engine. This is a vital safety step to prevent the engine from accidentally firing up. Use a long-reach socket and wrench, turning it anti-clockwise to remove the old plug.
With the plug removed, inspect it closely. If it appears black, is covered in soot, or looks oily, it's a clear indication that it needs replacing. An old or worn spark plug is a frequent culprit behind difficult starting issues. When installing the new spark plug, hand-tighten it first to prevent cross-threading. Then, use your wrench to tighten it only to the point where you feel resistance. Over-tightening can shear off the top of the plug and ruin it, requiring another replacement. Finally, reattach the HT cap securely.
Checking and Replacing the Air Filter
Another vital component for engine health is the air filter. A clogged, oily, or excessively dusty air filter can severely impede your mower's performance by restricting airflow to the engine. This can lead to reduced power, increased fuel consumption, and even engine damage.
The air filter is usually located near the top of the engine, encased within a plastic or sometimes metal cover. To remove the cover, you'll typically need to unscrew a few bolts or simply pull off snap fittings. Once the cover is off, the air filter should be easily accessible. If it looks generally clean, a gentle tap can help dislodge any loose dust or debris. However, if it appears soiled, oil-stained, or heavily clogged, it's definitely time for a replacement. Installing a new, clean filter will significantly improve engine efficiency and prolong its life. Ensure the new filter is fixed securely in place, and then re-secure the cover.
The Most Critical Step: Lawnmower Oil Change
Perhaps the most critical aspect of lawnmower maintenance is the oil. Just like in a car engine, the oil lubricates moving parts, reduces friction, and helps cool the engine. Too little oil, too much oil, or old, degraded oil can cause severe damage to your machine, potentially leading to complete engine failure. If your oil is black, very thick, or the level is significantly low, it's absolutely essential to replace it immediately with brand new oil.
When to Change Your Lawnmower Oil
Generally, it's advised to replace your petrol lawnmower's oil at least once a year, especially at the start of the mowing season, or every 25 hours of operation, whichever comes first. However, as mentioned, if you notice the oil is black, very thick, or the level is consistently low despite topping up, it's time for a change regardless of the time frame.
Choosing the Right Oil
It is paramount to use oil specifically designed for lawnmower engines, and, crucially, the correct viscosity grade for your specific mower model. This information will always be detailed in your lawnmower's user manual. Using the wrong type or grade of oil can lead to inadequate lubrication and premature engine wear. Do not use automotive engine oil unless explicitly stated in your manual.
Step-by-Step Oil Replacement Procedure
- Warm Up the Engine: To make the oil easier to drain, run your lawnmower for a few minutes before changing the oil. This warms up the oil, making it thinner and allowing it to flow out more easily.
- Prepare for Drainage: Ensure the spark plug lead is disconnected for safety. Place a suitable receptacle, such as a large drain pan or old container, directly underneath where the oil will drain.
- Locate and Remove the Oil Cap/Dipstick: The oil cap often has a dipstick attached. Remove it to allow air to enter as the oil drains, facilitating a smoother flow.
- Drain the Old Oil: There are two common methods for draining the oil:
- Tilting Method: Carefully tilt the lawnmower onto its side, allowing the old oil to pour out into your prepared receptacle. When tilting, always tilt the mower backwards, pushing the top of the handles towards the ground, never to the side. This prevents fuel from spilling into the air filter or exhaust.
- Oil Extractor Method: Alternatively, you can use an oil extractor pump, which is often cleaner and less messy. Insert the extractor tube down the dipstick hole and pump out the old oil.
- Ensure Complete Drainage: Allow ample time for all the old oil to drain out. You might need to gently rock the mower back and forth a few times to ensure every last drop is removed.
- Clean Up Spills: Once the old oil has been fully removed, bring the machine back to its upright position. Use an old rag to wipe away any oil that may have spilled onto the machine's exterior.
- Proper Oil Disposal: It is crucial to dispose of spent engine oil responsibly. Never pour it down drains or into the ground. Take the used oil to a registered point for disposal, such as a local recycling centre, garage, or hazardous waste facility.
- Add Fresh Oil: Now, it's time to add the new, clean oil. Refer to your mower's manual for the specified amount. It's often easier to use a funnel and add the oil gradually to avoid overfilling.
- Check the Level: After adding the oil, insert the dipstick, remove it, and check the oil level. Add more if needed until it reaches the correct 'full' mark on the dipstick. Be careful not to overfill, as this can also cause problems.
- Replace Oil Filler Cap: Once the correct level is achieved, securely replace the oil filler cap.
Blade and Deck Maintenance for a Perfect Cut
While the engine ensures your mower runs, the blades and deck are responsible for how well it cuts. Neglecting these areas can lead to an uneven, ragged lawn and inefficient operation.
Cleaning the Lawnmower Collection Bag
Wet or fresh grass, especially during spring, can be particularly sticky and accumulate inside your collection bag or box. When this dries, it becomes incredibly difficult to remove and can hinder airflow. Wash out the inside of your collection bag regularly, ideally after every few uses, and allow it to completely dry before its next use. A clean bag maintains properly collected grass clippings and ensures optimum airflow, allowing the bag to fill to its maximum capacity.
Clearing the Underside of the Deck
Just like the collection bag, the underside of your mower's deck can accumulate a thick layer of dried grass and debris. This build-up reduces cutting efficiency, can cause vibrations, and promotes rust. To clean it, first ensure the spark plug has been removed for safety. Then, tilt the mower backwards by pushing the top part of the handles towards the ground (never to the side, as this can cause fuel or oil to leak into undesirable parts of the engine). Once tilted, use a stiff brush or a scraper to remove all the old, dried grass and dirt. For stubborn grime, a hose and brush can be very effective.
Inspecting and Sharpening the Blades
Even the best petrol lawnmower won't deliver a clean cut if its blades are blunt or damaged. Inspect your blade(s) closely. Look for chips, dents, or signs of dullness. If the blade is slightly chipped or blunted, you can sharpen it yourself using a flat file or an angle grinder. When sharpening, it's crucial to maintain the appropriate cutting angle of the blade and to ensure it remains balanced. An unbalanced blade can cause excessive vibration and damage to the mower's engine. If the blade is severely damaged, bent, or if you're uncomfortable sharpening it yourself, it's best to have it professionally sharpened or replaced.
Other Important Checks for Overall Health
Checking the Controls
Your mower's controls, typically a lever pressed against the handle for blade engagement and a second lever for self-propelled models, must function freely and smoothly. As part of your service, ensure these controls are not sticking or offering resistance. Lubricating the joints with a suitable grease, such as WD40, can often resolve any stiffness and ensure smooth operation.
Adding Fresh Petrol to the Tank
If your lawnmower has been in storage for an extended period, especially over winter, the petrol in the tank can degrade. Old fuel can lead to starting difficulties, misfiring, or even engine failure. It's highly advisable to drain any old fuel from the tank and refill it with fresh petrol before the mowing season begins. This simple step can prevent many common fueling issues.
Comprehensive Lawnmower Service Checklist
| Component | What to Check | Action If Needed | Frequency |
|---|---|---|---|
| Nuts & Bolts | Security, tightness | Tighten or replace | Before each use / Annually |
| Pull Cord | Fraying, wear | Replace | Annually / As needed |
| Spark Plug | Colour (black, oily, sooty), wear | Replace | Annually / Every 25 hours |
| Air Filter | Clogging, oiliness, dust | Clean (tap) or replace | Annually / Every 25 hours |
| Engine Oil | Level, colour (black), consistency (thick) | Drain & replace with correct grade | Annually / Every 25 hours |
| Collection Bag | Grass build-up, airflow | Wash & dry thoroughly | After each few uses |
| Underside Deck | Dried grass, debris | Scrape, brush, wash | Periodically / As needed |
| Blades | Sharpness, chips, damage, balance | Sharpen or replace (professionally if needed) | Annually / As needed |
| Controls | Free movement, stiffness | Lubricate joints | Annually / As needed |
| Fuel Tank | Old or stale petrol | Drain & refill with fresh petrol | Before long storage / Seasonal start |
Frequently Asked Questions About Lawnmower Servicing
When should I replace my petrol lawnmower oil?
It's generally recommended to replace your petrol lawnmower oil at least once a year, typically at the start of the mowing season, or after every 25 hours of operation, whichever comes first. However, if you notice the oil is black, very thick, or the level is consistently low, it should be changed immediately, regardless of the time frame.
Why do I need to service my lawnmower?
Servicing your lawnmower extends its life, keeps it running at its optimum performance level, reduces the risk of mechanical breakdown, and ensures your lawn looks its best. For many models, it's also crucial for maintaining your manufacturer's warranty.
What type of oil should I use for my lawnmower?
You must use oil specifically formulated for lawnmower engines. The correct viscosity level and specification (e.g., SAE 30, 10W-30) will be clearly stated in your lawnmower's user handbook. Do not use standard automotive engine oil unless explicitly recommended by the manufacturer.
Can I sharpen my lawnmower blade myself?
Yes, you can sharpen your lawnmower blade yourself using a flat file or an angle grinder. However, it's crucial to maintain the original cutting angle and ensure the blade remains perfectly balanced. If the blade is severely damaged, bent, or if you're unsure, it's best to have it professionally sharpened or replaced.
What are the signs of a bad spark plug?
Signs of a bad spark plug include difficulty starting the machine, rough idling, misfires, or reduced engine power. When inspected, a faulty spark plug may appear black, covered in soot, or oily.
How often should I clean the underside of my lawnmower deck?
The underside of your mower deck should be cleaned periodically, ideally after every few uses, especially when cutting wet or fresh grass. Accumulated grass can harden, reducing cutting efficiency and promoting rust. Always ensure the spark plug lead is disconnected before tilting the mower to clean the deck.
Conclusion
Servicing your lawnmower might seem like a chore, but as Adam Woolcott and countless other gardening enthusiasts know, these simple procedures are key to keeping your mower in tip-top condition. By regularly checking and maintaining your machine's vital components – from the oil and spark plug to the blades and deck – you'll ensure many hours of hassle-free mowing. This season, take pride in your garden and the reliable machine that helps you maintain it. Happy gardening!
If you want to read more articles similar to Mastering Your Mower: A Comprehensive Service Guide, you can visit the Maintenance category.