Will four stroke oil damage two stroke engine?
You can use four stroke oil for a (very) limited period in a two stroke engine in an emergency.
However it is not formulated for two stroke engines and is not recommended.
What if I added 4 stroke seadoo oil in a 2 stroke 2001 rxdi seadoo if I have not started it yet should I siphon it out and add 2 stroke?
When comparing to a two-stroke engine, the four-stroke engine has the following advantages. Fewer emissions. Since the crankshaft has its own oil reservoir there is no need to add oil to the fuel, meaning there is no oil burned in the fuel. Better fuel consumption. The four-stroke engine complete a full cycle in four-stroke. This gives it greater control over which ports open at which times. On a two stroke engine, fuel and air is…