Ignoramus8745 wrote:
Picked up a "2.98 kW" (4 HP?) 60 gallon Speedaire compressor with a
self described "bad motor" for $50.

I am kinda hoping that the motor is not actually bad.

Upon inspection, it seems that the motor has four terminals
1,2,3,4. Terminals 1 and 4, supposedly, are for line in, if i read the
label right.

There is no diagram for the rest, so, would it be correct to assume
that I need to connect 1 and 2, and 3 and 4? Or, if the rotation is
wrong, 1 and 3, and 2 and 4?

i
Probably not. I am guessing it is a dual-voltage
motor, and likely you tie 2-3
and tape up for high voltage, and probably
something like line in on 1-2 and 3-4
for low voltage. But, it could be a reverisble
motor. Usually, reversible motors
do not have 4 leads, but have a terminal board
insde where you reverse two
wires to change the direction. Is there a nameplate?
If not, there might be a paper label somewhere
under a cover with the wiring
instructions.

Jon