Are 2 stroke and 4 stroke oils interchangeable? The short answer is ….no.
In both motors, the oil lubricates the metal parts, keeping them from seizing together, but they do it in completely different ways.
2 STROKE MOTORS
2 stroke motors have no oil circulation system and the oil is added to the gas the motor uses. The oil then burns along with the gas. The oil and gas coat the cylinder as the piston moves up and down providing lubrication and are burned in the combustion chamber.
Along with the gas, the oil is completely burned (which produces smoke and ash) and this is the reason the EPA no longer allows 2 stroke motors
4 STROKE MOTORS
4 stroke motors have an oil circulation system and use a splash type system to coat the pistons and other motor parts. The crank lays in the oil pan being lubricated by the oil as it turns. The splashing that occurs as it rotates in turn lubricates the cylinder walls, wrist pins, bearings and other parts.
Because the oil is not being burned it continues to recirculate in the motor needing to be changed as part of your jet ski maintenance.
2 STROKE OIL VS 4 STROKE OIL
2 stroke motors burn their oil and the oil used in these motors is more refined and produces a lower ash residue when burned. Among the additives in this oil are components to aid in combustion and help limit smoking, detergents to clean carbon deposits, and anti-wear agents to help with lubrication.
4 stroke oil isn’t burned but is used over and over again. This oil is thicker than 2 stroke oil and is not designed to burn. The flash point for this oil is too low to be used in a 2 stroke motor. It also uses different additives consistent with it’s recirculating usage to prevent wear, corrosion and oxidation.
While the higher end synthetic oils may seem thinner, they still provide the same properties for burning or not, necessary lubrication and the appropriate additives for each engine.
Using the wrong oil will provide unwanted results as your engine operates and could cause irreparable damage.
For more information on 2 stroke oil see my article here https://thejetskistoreblog.com/what-oil-should-i-run-in-my-2-stroke-jet-ski
