I am working on an "emergency" gas-tank cap. In case that I am low on gas I want to use an air-pump to pressurize the tank a little bit.
Of course, I don't want to modify the original brass cap, and even a used one is too expensive because of shipping cost, so I got the idea to 3D print one, including the thread, in Nylon, with a little nipple for a 6-4 mm (OD-ID) PVC hose.
Can somebody tell me which thread is used on the gas-tank, please?
I have a Touring 1916 with round tank under the seat.
Do metal barrels have the same cap? Never thought about that, but would be an option, too.
