Fuel Shut Valve

[<TexasMan77>]

Question… Fuel Shut Off Valve:

Engine…Mercury 150 Saltwater / Carbureted

I have heard of two schools of thought on engine shut down at the end of the day. This is on the Texas Gulf Coast where summer heat and humidity rule.

One school suggests (requires installing and using a fuel shut off valve) starve the engine on the last shut down, leaving no fuel in the carburetor.

The other school says just shut it down…note that this group uses fuel additives like STA-BIL.

Any comments would be appreciated.

[<Mikey>]

Do not run oil injected engines dry. The reason is that as the fuel lines empty of petrol the fuel pump will fill them with oil, then the carbs get filled with oil. If you see someone at a ramp having difficulty starting an engine, then when is does start there's a huge cloud of smoke; that because he ran the engine dry the last time he used it.

Another issue to consider with multi-carbed engines is that as one carb 'runs dry' and its cylinder(s) stop firing, they suck water in from the exhaust system, leaving the engine with a belly full of water on the last shutdown. Do you really want the steel cylinder walls to have water on them till you next use the boat?