Does anyone out there have a John Deere L120 have a issue with the following it has a extra regulator box on side to keep battery charged while the electric PTO is working also need to know or would like a pic of how it is wired it shows voltage on the regulator when switch is off if anyone can help with pic of how theiers is wired or info would be greatly appreciative.

Do you have a volt meter? IF so, check the voltage across the battery with- Engine off Engine at high speed Engine at high speed with lights, PTO etc. on. Everything off should be 12.6 VDC. With engine running & full electrical load, it should be 13-14ish volts DC. Also switch meter to AC to see if there is any ACV present. There shouldn't be. IF you don't have 13-14 DCV across the battery at high speed, do the following- Disconnect the plug to the Voltage regulator and measure the ACV between the 2 Yellow?(non Red) wires. Depending on the charge system used, there should be something like 28 or 40 VAC MINIMUM. NOTE- That's AC Volts. IF you have the proper AC voltage, the alternator is OK and the problem lies with the voltage regulator or wiring.

If you are correct on your assessment, possibly the solenoid on the carb bowl is not actuating? Seals good inside?

Has it been verified that the solenoid below the carb is working? If you are concerned on compression, on this engine you want to know that both pistons are traveling and pulling the valve covers will tell you a lot. There you can confirm that all 4 valves are operating and that they have comparable lifts and are closing.