Do you use 2 stroke or 4 stroke motor oil?

You should use the appropriate oil for the type of motor it is. 4-strokes should have 4-stroke oil and 2-strokes should have 2-stroke oil.

my friend bought a used 4 stroke 4 wheeler and the first day the oil started shooting from the head,she took it back and he ran hoses from crankcaase to head, and the previous owner told her to use 2 stroke in crankcase.makes no sence unless hes rigged it up to work temporaraly.