Don't know where the fuel solenoid is on your model, but on my Max 22 it is located just above the oil filter and behind the throttle cable. My Max 22 was exhibiting the same symptoms. After browsing some forums I was also directed to the fuel shutoff solenoid. I pulled the solenoid and tested it on the bench. It would pull when the pull winding was energized (about 24 Amps) but the hold winding was not able to hold it in the pulled position when pull was released. I considered rigging it to just use the pull winding to hold it closed, but at 24 amps I think that it would burn up the winding pretty quickly. In any case, if you can pull the solenoid and test it at your dad's place it should be a pretty quick and easy test and let you know if you need to order a new one.
