Mowers, blowers, brush cutters and chainsaws are available in 2 and 4 stroke engines.  These types of engines are very different to one another and if you’re thinking of buying an engine, its really important to weigh up the pros and cons of both types.

How an engine works
Internal combustion engines work by mixing air and fuel inside a chamber.  The mix is then ignited with a spark plug, causing an explosion.  The explosion then forces a cylinder at one end of the chamber to move out.  This force is transferred to make other parts of the engine move. 

After this, the engine returns it to its original position for the next explosion.

The differences between 2-stroke and 4-stroke engines

A “stroke” is when an engine completes half a rotation.  A two-stroke engine makes one rotation for every explosion.  A four-stroke engine makes two rotations for every explosion.

Two-stroke engines have the fuel and oil (for lubrication) mixed together.  Therefore, you don’t have an oil inlet on the machine, and you only need to buy one type of fuel.  Two stroke engines generally:

  • are lighter
  • are louder
  • tend to run less evenly
  • less expensive

Four-stroke engines need to have the fuel and oil added separately.  You don’t need to worry about mixing two-stroke fuel in the correct ratio, but you will need to buy two separate fuels.  Four stroke engines can’t be used upside down or on their side.  Generally, 4-stroke engines are more:

  • powerful
  • complex
  • reliable and easier to start
  • expensive

Hire or buy?
If you are thinking of buying an expensive engine, have you considered the possibility of hiring instead?  Sure, if you need a mower every Sunday, then buy it.  But if you only plan to mulch your garden prunings a couple of times a year, then hiring is a great option.  Firstly, you don’t have to outlay much – and you also don’t have to maintain expensive machinery.  Keep in mind that hire companies will keep updating their equipment as well – you’ll always have access to the latest technology.

Deciding on which type of engine to buy

  • Heavy duty use  - four stroke
  • For use on steep slopes or angles – two stroke
  • Where reliability is important – four stroke
  • When you’re on a tight budget – two stroke
  • For large lawn areas – four stroke
  • If you have trouble manoeuvring heavy machinery – two stroke
  • For mulching large branches – four stroke

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