The solenoids for the early 80s Hondas are funny. Two of the pins are always hot and go to the ignition switch and the regulator/rectifier. The other two pins are for the solenoid's energizing coil.
It's easy enough to identify which is which if you have a multimeter handy.
First, make sure you have a good 30A fuse in place in the solenoid.
With the multimeter set to measure resistance, we're looking for continuity between two of the pins and one of the studs on the solenoid. Measure from one stud to each pin, in turn. Two of them should have a resistance near zero and the other two should read as Open Line. If you can't get any with a low resistance, try reading from the other stud (mark off which stud you get a reading from, this will be important later).
After identifying the two pins, these will connect to the red (or red/white) wires that lead to the R/R and the ignition switch.
The other two pins are for the solenoid's energizing coil and it doesn't matter which is which. One of the pins goes to the yellow/red wire leading from the starter button and the other wire goes to the green/red wire leading to the neutral/clutch switch diode. Or, you can skip the green/red wire and ground this pin directly to the frame. This bypasses the safety equipment like the clutch switch, so that the starter motor will work in any gear, whether or not the clutch is in.