The same as any other engine that doesn't mix oil into its fuel.
Lubrication in fuel vs lubrication using a separate system and 2-stroke vs 4-stroke are two entirely separate engineering decisions, that are in no way tied to each other. It's just that the most common types of 2-stroke engine use lubricant oil mixed in fuel, and the most common types of 4-stroke engines don't, and so they concepts are thought to be related to each other by most people who don't know much about engines.
2-stroke engines often go into handheld tools or dirt bikes that can't explode when you turn it upside down (at least, immediately), and since it eliminates the oiling system, premix is often chosen for these.
2-stroke engines also have great power densities (at the cost of fuel efficiency), which means those two often go hand-in-hand.
Tuna-Fish|2 years ago
Lubrication in fuel vs lubrication using a separate system and 2-stroke vs 4-stroke are two entirely separate engineering decisions, that are in no way tied to each other. It's just that the most common types of 2-stroke engine use lubricant oil mixed in fuel, and the most common types of 4-stroke engines don't, and so they concepts are thought to be related to each other by most people who don't know much about engines.
hatsunearu|2 years ago
2-stroke engines also have great power densities (at the cost of fuel efficiency), which means those two often go hand-in-hand.
jacquesm|2 years ago