We used to use a 1/8 pipe nipple to move the glass filter up to the carb and then we would get a metal bowl to replace the glass. That service door for the fuel pump can let in enough snow to cause an overheated glass bowl to break so we never took the chance. What a hell of a thing to get at. I run a removable filter just off the tank, then go down to a 12v Bendix tucked in between the tank and back fender. Then I go to the fuel pump and back up to the metal bowl filter at the carb. I only use the 12v at cold start up, and when I get vapour lock on hot running days. Because there is always the chance of a broken diaphram in the mechanical fuel pump, I carry a fitting, snap tied to the carb so I can go 12v direct without sewering the crankcase with gas. I have a metal deflector that shields some of the heat from the manifold on the fuel pump, but in tough going in spring I still get problems some time. As a rule, the newer your fuel pump the less problems with vapour lock.
