The difference between 2T and 4T engine
2 stroke engine or 4 stroke engine? While this sounds obvious to some of you, it isn't to everyone! Here are some explanations and memo-techniques to know how to differentiate these two types of internal combustion engines.
The 2-stroke engine
In a 2-stroke engine oil, air and fuel are mixed. This is why when we talk about fuel for 2-stroke engines we are actually talking about the mixture (oil + fuel). The piston rotates the crankshaft one revolution to complete a full cycle. The spark plugs fire once per revolution on this type of engine.
His advantages ? Its weight and reduced size make the 2-stroke engine an ideal engine for a hand-carried machine, such as a chainsaw or a hedge trimmer. The absence of an oil sump is also an important advantage since it allows the machine to be used in all positions, which is why it is mainly used for mobile tools (chainsaws, brushcutters).
The 4 stroke engine
Generally the engine has two filler pots, one for gasoline and a separate one for oil: do you have a 4-stroke engine? Above all, do not mix oil and gasoline for this type of engine! These two elements must not be in contact.
Unlike a 2-stroke engine, the piston rotates the crankshaft twice to complete one complete cycle. The spark plugs fire once every 2 revolutions in this type of engine.
The 4-stroke engine thus has a lower efficiency compared to the 2-stroke engine, but this makes it much less noisy! It also consumes fuel more efficiently.
Recognize an engine (2 stroke or 4 stroke)
To tell if a machine runs on a 2 or 4 stroke engine, just check the number and type of fill ports. These are where you add oil or fuel. If it only has one, then it is a 2-stroke engine. If it has 2 then it is a 4 stroke engine.
Even simpler technical memo for the most novice among us, when the machine can be carried at arm's length it is generally because it has a 2-stroke engine. On the other hand, if the machine is bigger and it can be difficult to carry then it is a 4-stroke engine! Be careful, however, because it is also possible that a mower-type machine runs on diesel so the best thing is still to ask the seller for advice to be sure not to make a mistake when buying.