Are the front and rear pump motors identical?
Ebay says special number.

Is the rear pump the one closest to the fender?

What's the easiest way to swap it?
Even with the headlight assembly out I wonder if the air filter
box is in the way. Maybe can yank it up and out with 12" hemostats
and hope there's enough slack with the rubber tubing to reconnect?

It looks like some plastic in-line filters, do those ever fail?
(That's suggesting there's a perpetual machine, I should know better.)

I have an old pump in my junk that shows no sign of life when hooked up
to 13.8 volts, and I see what looks like a motor winding 3.5 ohms one way
and 3.9 ohms the other way. What's across the motor winding?
Has anyone pulled a pump apart to see if there's something repairable?

Thanks, Bill