3 hp lightwin

[tugboat1870]

I'm trying to get my old lightwin running after quite a few years in storage. It turns over well and has compression and spark.
The front panel states "mix 1/2 pint of SAE 30 outboard oil per gallon of gasoline.
Question; what is sae 30 outboard oil? I think that this is different from 2 cycle engine oil. Am I correct?
Thanks in advance for any replies!

[tugboat1870]

OK, I'm past the "OIL" issue above but now need to ask about the water pump impeller for this outboard; The impeller can be installed in either of 2 positions in the pump housing. Which position is correct?