This is a preferred method to plumb and fuel a simple airplane with an exposed engine or just cheek plates.

That third nipple is sealed. If your tank already has a third hole in the plug I would just put a short piece of line on it and plug it. Fueling with a split in the carb line like this with a short piece of fuel tube is a good practice and there is no chance of flooding the carb. In addition in the case of a rear needle carburator its makes replacing the line far easier than trying to slip it back on the nipple in that tight space between the firewall and the engine.

also this method requires no additional internal tubes or extra clunks.


John