Basics of the 2-stroke engine

If you purchase, let’s say, a petrol-powered chainsaw, it will undoubtedly be powered by a two-stroke engine.  

No one is born knowing instinctively how to care for and run one of these and it can take time to get used to them. 

A two-stroke engine is a type of internal combustion engine where the cycle is completed in one turn of the crankshaft (as opposed to two turns in a four stroke engine). One up, one down motion – hence two-stroke. 

Here are a few tips and pointers regarding two-stroke engines. 

Two-Stroke engines are relatively simple, and therefore easy to use once you have got used to them, easier to maintain than four-stroke engines with fewer parts to go wrong and are known for delivering a high power to weight ratio.

Here are a few things worth bearing in mind –

• The spark plug ignites once for every turn of the crankshaft

• You have to mix the petrol with engine oil and get the mix right. We recommend the following ratios:

             Synthetic Oil: (red or blue) 40:1     Mineral Oil: (green) 25:1

• The two-stroke engine needs three things to work, air, fuel and a spark. If your engine won’t start or there is a problem, it is likely to be one of these, or lack of one of these, that is causing it.

• Two-stroke engines are very easy to flood, try not to over crank when starting. Click here for  Engineer’s Tip how to start a 2-stroke engine