How Long Should Engine Run After Shutting Off Tank?

[BlackSmoke]

While winterizing, I shut off valve to gas tank under bow and it took five to 10 minutes for my '69 OMC 120 hp stern drive engine to run out of gas at idle. Made me wonder if valve leaks. Water separator still had liquid in it when I took it off afterward. Should it run that long?

 

[SlowlySinking]

Re: How Long Should Engine Run After Shutting Off Tank?

Hi BlackSmoke, that's seems about right, at idle the engine will run quite a while, you will typically have all carb bowls full of gas and the lines and primer will also be full, that's a lot of gas. The fact that it finally runs out indicates that the shut off valve works, one point, on two cycle engines you always let it run out at an idle, revving the engine risks having it run out at high RPM's and then there's little or no oil on the bearings as the engine comes to a stop. Damage is possible, good luck, Ken