cjohnson

Very old ones were pressurized, and did not vent. The line to the motor was a pair, with one side returning pressure to the tank. No one has made one like that in many years, though. All modern outboards (as far as I know) use a non-pressurized tank, which will have a vent screw in the cap. The hose shouldn't drip if the vent is left open. If your tank does not have a vent screw in the cap it may be a pressurized type. The giveaway is the hose -- double hose = pressurized. With that kind of tank, it was sometimes necessary to leave the cap loose to avoid leakage. Well, wait, now I think of it, at my East Coast place I do have a 1970's vintage outboard with a no old non-pressurized metal tank that has no vent screw. I don't use that motor much. The cap vents poorly if left on tight, and on very hot days I leave it loose to avoid the hose dripping. Maybe similar to what you have. I doubt there is a rebuild kit for it, but a new plastic tank should work as a direct replacement no problem.