Frequently Asked Questions

Choosing a Lawnmower

Q: What is the difference between a rotary lawnmower and a cylinder lawnmower?
A: A rotary lawnmower uses either a bar blade or individual swing blades mounted on a circular carrier plate. The grass is cut with a scything action as the blades rotate. Rotary lawnmowers generally have four height-adjustable wheels and a rear-mounted grassbox. A cylinder lawnmower cuts your lawn with a scissor action, giving the lawn an exceptionally fine finish. A fixed bottom-blade and rotating cutting cylinder work together to cut each blade of grass perfectly. Most cylinder lawnmowers run on rollers, which follow the contours of the lawn far better than wheels. A front-mounted steel grassbox collects the grass clippings.
Q: Should I choose an electric or a petrol powered lawnmower?
A: This is largely a personal choice, but under certain conditions, there are overriding factors which must be considered.

Electric lawnmowers offer ease of use without requiring special maintenance or operating procedures. Their use is limited by the maximum recommended cable length, which must not be exceeded due to the possibility of voltage-drop and the resulting motor damage. Certain garden layouts, which have trees and/or other obstructions on the lawn, can be frustrating to mow due to cable management issues. Overall, under the right conditions, an electric lawnmower is simple to operate and requires little maintenance.

Modern petrol lawnmower engines are reliable and easy to start, provided the correct maintenance and operating procedures are followed. Petrol-powered lawnmowers offer increased power over electric lawnmowers, and larger areas can be covered more easily as there is no electric cable to get in the way. For large properties and/or tough conditions, a petrol lawnmower of the correct rating is essential.
Q: How much power do I require?
A: The manufacturer's power ratings do not tell the whole story. The overall quality of a petrol engine is more important. Better engines will have a cast-iron bore, ball bearings on the crankshaft and superior-quality filters and governing systems. It is important to select the correct engine for the task, so it is essential to get good advice from a knowledgeable salesperson.

Electric motor power ratings refer to the motor's power consumption. A lawnmower with the standard width of 460mm should have an electric motor rated at a minimum of 1800 watts. Larger electric motors disipate much of their rated power as heat. Remember, bigger is not always better.

Using a lawnmower

Q: What is the correct fuel for my petrol lawnmower?
A: Unleaded petrol of the highest available octane level. For 2-stroke engines, it is essential that high quality 2-stroke oil is mixed with the petrol at the correct ratio, as recommended by the engine manufacturer.
Q: How do I set the level at which the lawnmower cuts the grass?
A: With a rotary lawnmower, this is achieved by adjusting the wheel height either individually or with a lever setting all four wheels simultaneously, depending on the lawnmower design.

The posistion of the bottom blade on a cylinder lawnmower determines the height at which the grass is cut. Adjusting the front roller height will allow an accurate setting to be achieved.
Q: What is the general procedure for starting a petrol lawnmower engine?
A: The following steps apply to the majority of machines:

  1. Ensure there is fuel in the tank and open the fuel tap, if present.
  2. Some mowers have an ignition switch - ensure this is set to the 'on' position.
  3. Move the choke lever to the closed position. On machines equipped with a primer bulb, press (usually 3 times) to pump fuel into the carburetor.
  4. Pull the starter rope firmly until the engine fires.
  5. On engines equipped with a choke, move this to the open position.
  6. Remember to close the fuel tap when the engine is turned off.

Maintaining a lawnmower

Q: How often should the oil be checked and changed?
A: Engine oil must be checked every time the lawnmower is used. When mowing for an extended period, the oil level should be checked throughout the day. It is recommended that engine oil be changed every 25 hours of use. On a new engine, the first oil change should occur after the engine has worked for 5 hours. Unless otherwise recommended, use good quality SAE30 or SAE40 engine oil in all air-cooled petrol lawnmower engines.

2-stroke machines have their engine oil mixed with the petrol, and therefore receive new oil whenever the fuel tank is filled. However, certain 2-stroke engines have a separate oil chamber for lubricating the governor and lower crankshaft bearing - check the operating manual for maintenace details.
Q: What is the importance of air-filter maintenance?
A: A petrol engine operates by the combustion of a mixture of fuel and air. Any foreign particles (dust, sand, grass-cuttings etc.) that enter the engine via the air-intake will damage the engine. Cleaning and/or replacing the engines air-filter are vital to ensure long engine life.
Q: When should the blades be replaced or adjusted?
A: Rotary lawnmower blades should be replaced when worn. Inspect the blades periodically - a straight cutting edge is more important than actual sharpness. As the blades also develop the vacuum that collects the grass cuttings, poor grass collection is also an indicator that the blades may be worn.

Regular adjustment of cylinder lawnmower blades is essential in achieving the fine cut that these machines are capable of delivering. When the blades are correctly set, there should be a shearing action when the cutting cylinder makes light contact with the bottom blade - a piece of paper can be used to check the effectiveness of the cutting action. If the blades are set regularly, the bottom-blade will wear evenly, and can replaced when area of contact restricts the cutting cylinder rotation. When the blades can no longer be accurately set, the cutting cylinder must be professionally sharpened.