[oil pan 4]

A little bit smaller pulley made a huge difference.
Holding at about 1/2 throttle it popped off the 130psi relief valve. Before with the slightly larger 2.2 inch pulley it struggled hard to build up to 90psi, 100psi seemed impossible.
Edit:
Today I welded an extension arm onto the throttle lever plate and connected the diverter valves "bull whip" and made a rudimentary throttle control and it works perfect. No need for a complex governor. I didn't think it would work but figured I would give it a try.
Now I can sell this and make about $100 over what I put into it.
Craigs List 3hp briggs and Stratton, $30
Scrap yard air compressor and tank, $15
New diverter valve, $50
Idler pulley, $9
Ask $240, but will take no less than $200.

Next project resurrect another scrap yard air compressor.
On this one I was going to junk the compressor and save the tank and 110/220 volt motor for later. Then realized the compressor bores were just a little rusty, not pitted and it was full of dirt. After I drained the slug out of the air compressor (had to keep poking the oil drain hole with a wire to keep the oil/slug draining) I hand honed the bores to restore the cross hatching.
I am going to convert the motor voltage from 110 to 220, by swapping wires around. Then I will power factor correct it, of course.
The motor is getting switched to 220 because I am going to put a 10% bigger pulley on the motor, run it faster and get more air out of it. Right now its rated for 22 amps at 110 volts, put a bigger pulley on the motor and it will surely flip a breaker on any house hold 110v circuit that is up to code.
This is going to be an actual mobile compressor, unlike my other compressors that are in the dungeon and never see the light of day.
As of now my only mobile electric air compressor is the little blue one that is getting assimilated into a gas/electric hybrid.