Is this an electrical part or a mechanical part? You be the judge. It is on the chassis, so I put it under that category.
Fuel Pump Assembly, partially removed from bike. Note 3 small holes to admit fuel to the housing. There are 3 more on the opposite side.
Stator output from fuel pump winding (loaded).
Mahle KL97 fuel filter as used by OSSA
Fuel Pump Operation
There is a fine screen on the suction side of the pump to prevent debris from getting into the pump.
Note the position of the fuel filter. Fuel flows through it in the direction of the arrow and is constantly circulating through it (not just once through). That way, the outlet pressure is not affected by dirt in the filter. I am told that the dirt in the filter is primarily carbon residue from the DC motor's brushes.
There are two quick-disconnect fittings inside the fuel tank. A special tool (available at auto parts stores) is required to separate them. In the photo, an electrical connector is partially obscured from view by the male side of a quick-disconnect fitting.
The pressure regulator is not adjustable.
Fuel pump assembly with parts annotated
Credit: agcoauto.com Electric fuel pump cutaway view