The nipple for the pump cover is needed on applications that do not have a pulse hole for the fuel pump. For the pump to work, a nipple must be added to the pump cover and a tube run to another nipple on the crankcase of the engine. This will provide a pulse for the fuel pump to work.

Tower has plenty of nipples for different glow engine carburators which I think would also work but I have been unable to find any taps to create the threads. They all seem to be metric.

Jim