The HS check valve is a little brass spud sticking up out of the venturi right where the high speed fuel nozzle should be.

The accelerator pump can be spotted by looking at the throttle arm shaft. There will appear to be a device riding against a flat place on the throttle shaft.


There's another device on some Walbro's called a governor that is a brass spud (3) near the throttle arm(2). This is undesireable and is usually removed and the hole filled with a lead plug.