Dump/siphon/drain it as best as possible and as long as you haven't tried to run it, you should be able to fill it with petrol and fire it up! The petrol will dilute the residue sufficiently.
Ordinary 87 gasoline, the same you put in a car. It depends if it is a four stroke or two stroke engine. If the engine has a separate filler for oil then plain petrol will do. If there is no separate filler the 25 to 1 petrol /oil mix should be OK.
to put the oil in the lawnmower's crankcase would be fine, so long as it is an appropriate viscosity.
The engine will overheat & seize due to lack of oil. A 2 stroke needs a fuel oil mix to lubricate it's moving parts.
SAE 10w30 weight synthetic oil.
0.6 litres
What type oil do you put in your 2001 Peugeot 607 2.0 petrol?
You get engine damage from lack of lubrication
Drain the oil and gas out of the crankcase and put oil back it should be OK
Drain the oil and catch it in a clean container if you intend on reusing the same oil . Then replace the plug and place the correct amount of oil in the motor.
The engine floods and you have to wait for the lawnmower to drain before you start it up again or it might start smoking.
You put petrol in it, start the engine, and it goes.
Apparently you didn't crank it up. You are still here. Nothing except it may clean out some old dirty oil. Remove the gas and the oil and discard same. Refill the oil section and refill the gas tank. Don't do that again.