Clean air regulations virtually killed off the two-stroke, which is renowned for sending plumes of toxic blue smoke into the air, but it refuses to die.
A two-stroke engine needs only two strokes (up and down movements) of the piston for each crankshaft revolution. The more common four-stroke requires the four phases of "suck, squeeze, bang and blow" in order to perform the same task.
The two-strokes used in Japanese motorcycles were happily more sophisticated and nowadays these classic models are revered for their heritage looks and exhilarating performance. Prices for them are rising.
The two-stroke engine fitted to the East German Trabant car, which came to symbolise the fall of the Berlin Wall, was famously dirty too, but it has also been forgiven now that far fewer of the runabouts are on the roads.
The Trabant.
In the 1970s, a two-stroke motorcycle made in Japan was the dream of many a teenager. The Yamaha RD250, Suzuki GT 750 and Kawasaki 750H2 were all wild machines. They offered dramatic acceleration and top speeds at a time when fuel consumption and toxic emissions were not so much in focus.
Some 40 years later, hardly any new vehicles are fitted with a two-stroke engine. Low-tech versions of the motor are still found in machines like lawnmowers, chainsaws and marine outboard motors.
Surviving two-strokes are revered by enthusiasts and restored examples of high-performance motorcycles change hands for considerable sums of money. The same applies to well-kept Trabants.
The introduction of the Euro 4 emissions limit finished off the two-stroke in most European markets, although plenty are still in use in Asia.
A few companies such as KTM still have two-stroke models in their two-wheeler range, according to Till Ferges of the German magazine Motorcycle News. For carmakers, the technology is completely outmoded. No two-stroke car could hope to comply with today's stringent clean air rules.
Two-stroke power was popular in the former communist eastern half of Germany, mainly because cars and motorbikes with these engines were far cheaper to produce. The motor is less sophisticated than a four-stroke petrol engine and far fewer parts are needed to make it. It is also easier to maintain.
The last of three million Trabants left the production line in 1991 and more than 30,000 of them can still be found on German roads.
The downside is that two-stroke engines cannot match the longevity of four-stroke motors. A defective oil pump can quickly cause a seizure which reduces the engine to scrap metal.
Two-stroke motorbikes from Japan were high-revving machines, which leads to more mechanical wear. As a rule of thumb, engines like these will last for between 50,000 and 60,000 kilometres before a strip-down and rebuild is called for. Replacement parts are also expensive.
Refuelling a two-stroke can be a pain, too, since modern petrol stations seldom have an oil dispenser to ensure the right mixture - usually an oil/petrol ratio between 1:25 and 1:100.
The Yamaha RD 350 is a classic example of a bike with a two-stroke engine.
A Trabi owner will not stray far from home without a can of two-stroke oil in the boot. For every 20 litres of petrol pumped into the tank, the owner has to pour in half a litre of special oil.
Two-strokes from Japan had a throttle controlled auto injection system which meant the owner did not have to mess around with topping up the oil.
There are no oil changes, since the lubricating oil is contained in the petrol-oil mix and problems like exhaust gaskets or stripped threads on screws and joints are easy to fix.
One way of keeping a two-stroke engine in good working order is regular maintenance such as de-coking.
This means removing the carbon deposits produced during combustion from the piston, cylinder head and exhaust. It can be done mechanically or by using chemical solvents.
