Classic bike enthusiasts have started to collect 2 strokes in ever increasing numbers. With manufacturers phasing out their 2 stroke range due to emission problems, the availability of collectible machines has grown dramatically.
The working principles of a 2 stroke are the simplest of all internal combustion engines, with the least number of moving parts. The strengths of the 2 stroke design are its superior power-to-weight ratio (compared to a 4 stroke unit), and its ease of maintenance. However, they do require more combustion chamber maintenance than a 4 stroke due to the oil burning characteristic.