Fuel Valve solenoid for Searay Sundancer 270 Onan Generator Question

[skysvr]

Hello. I recently purchased a 1990 Searay Sundancer 270. The Onan generator has not been run in a while. I noticed no fuel going to the unit. Traced line back to a solenoid (Skinner Honeywell). Can anyone tell me how this works and where it gets its power from? It has a purple and black wire but no power when the ignition is on. It has a screw on top with an arrow that points to on.

I also apparently have a bad fuel sender unit. There is about four inch clearance to get this out. Does anyone know where to get a replacement that will fit? Tank is 100 Gallon. Original part number was 211755.

Thank you

Jim