My family just bought a new motor for the pontoon at our cabin. In the interest of longevity, my dad has instituted a policy requiring the gas be run out of the motor after every trip. I believe doing so is absolute nonsense. Besides my skepticism concerning the practice's benefit, I've also found it to be time consuming- generally in the neighborhood of 2.5 beers before she finally dies. Is running the gas out worthwhile?

U can run the gas out after a usage or pay some grease monkey mega bucks to clean out the gunk later. I have 4 out boards motors and have always ran the gas out after each use.

It depends on how long the motor will sit between trips; a day or 2 no problem, a couple of week's problem.

It depends on the motor. It is a single carb w/o vro go for it. It the motor has vro do not do it. it will fill the carb with oil. If it has multi carbs. do not do it. if one runs out of fuel before the other you risk damaging the cylinders that aren't getting fuel oil mix. If it is a 4 cycle you can do it. read the manual.

all you are doing is wasting time, money, and gas. Oldtimers thought that running the gas out of a motor would stop it from getting gummed up from sitting. gas will still sit in the carbs, even after the motor"runs " out of gas. so it will still get gummed up. If your boat is sitting for long periods of time. put a fuel stabalizer in the gas. If you use it every week or every 2-3 weeks the gas will be fine in it. Like I said your just wasting time, gas, and money running it out of gas

Very possible you are actually damaging motor.  First, even in single carb motors, the top cylinder will usually lean out first, letting it run without lube while still running on the bottom.  This problem is greatly multiplied if you run 3, 4, or 6 cylinder motors and multi carbs.  Granted, at idle the motor only needs a minute amount of oil but it's possible it may not be getting any.   Second, you are completely drying out the inside of the motor, leaving no oil film protection against even the smallest amount of condensation that can occur inside the motor, and trust me, the do get condensation just sitting out with the sun shinning on them in the early morning, very much more so on cool/cold nights.

If the motor is used even every month or two, you will probably not have much of a problem.  If being stored, it's much better to drain the carbs and purge the fuel system than running the gas out.

I've got a '83 50hp Merc and I never run it out after each use and I have have zero problems with it.  I use it about once every two weeks, but sometimes it can sit for a month without use.  Then in the winter I put some Sta-bil in the gas and run it a little, then come spring she starts right up.

I've got a 2005 Merc 9.9 4 stroke.  The manual recommends running the gas out.  Funny thing is, once I disconnect the fuel line, the engine runs and runs and runs on the little gas left in the line.