Run Engine out of gas before leaving dock?

[notarealone]

Had several guys get into this discussion at a local Bass Tournament.<br />When removing your boat at the end of the day and you are not going to use it for several days or weeks, should you unplug the fuel line from the motor and run the motor till it stops? There-by emptying the carb bowls.<br />Have heard several arguments for and against this idea. What ideas do you have on this? Serious replies only, please.

 

[AJ168]

Re: Run Engine out of gas before leaving dock?

I've heard both sides of it. Leaving the old gas can clog up the carbs, but the oil in a 2 stroke mix is a good thing to be left on the cylinders. I'm not sure about 4 strokes. I go with a happy medium before storing the boat. Run it until it just starts to die out. This way the fuel lines and carbs are dry but there's still enough fuel in the cylinders to keep them lubricated.

 

[Mark42]

Re: Run Engine out of gas before leaving dock?

Running it dry is probably more destructive than any varnish that can form from about 2 oz of gas evaporating from a fuel bowl. When running it dry, the needle and roller bearings will probably be OK, but those rings will wear fast.<br /><br />If you really really really want to drain the fuel, use the drain plugs in the float bowls, or remove the bowls.

 

[KRS]

Re: Run Engine out of gas before leaving dock?

By running it dry, you are effectively running it in a lean condition until it dies, leaning an engine increases wear, heat, etc.

 

[trog100]

Re: Run Engine out of gas before leaving dock?

"Have heard several arguments for and against this idea"<br /><br />if there was any real advantage to be gained from doing it the arguements would not exsist and the benefits would be apparent..<br /><br />when things go round and round it usually means it dont matter either way..<br /><br />trog

 

[Pony]

Re: Run Engine out of gas before leaving dock?

around here almost every boat is used maybe once every few weeks all through summer and then that is it. I, like the others have said, think running the carbs dry would cause more bad than good. <br /><br />Knowing that my boat could sit for a few weeks without use put some stabil in almost every tank to make sure the gas stays good. The small amount of gas in the carbs isnt going to do much in only two weeks time. I do however unplug the fuel line at the motor, so that pressure from the tank that builds up over time doesnt leak fuel into my carb. Even that is more for my peace of mind. <br /><br />Basically....a couple weeks its not an issue, a couple of months, fog it

 

[Richard Petersen]

Re: Run Engine out of gas before leaving dock?

How many of you hear a " squek, squek " when the engine stops? Have you ever pulled a head off 2 or 3 days later and ran your finger along the cylinder walls? I thought so. It does not dry out and remove the oil at idle. There is no heat to cook the oil off. Most engines if idled should have rich mixtures for smooth shifting with no stalling. There is no wear.... Theoretical crap.

 

[Drowned Rat]

Re: Run Engine out of gas before leaving dock?

One reason I heard is that on a multi cylinder engine, not all the carb bowls run out of fuel at the same time. So... for example, 3 of 4 cylinders may still be firing, but the 4th cylinder has already run out of fuel, and that would be BAD! A good decarb once or twice a year keeps any sludge clear that might have accumulated from leaving the bowls full. I don't run mine dry.

 

[Silvertip]

Re: Run Engine out of gas before leaving dock?

If you are using a fuel treatment there is no need to run the engine out of fuel.

 

[WillyBWright]

Re: Run Engine out of gas before leaving dock?

There are certain motors that you really don't want to do that with. Johhnyrdes with VRO, and carbureted Merciners with oil injection. As the gas runs dry, oil is still pumping in those motors. (Most others shoot the oil directly into the motor.) That often means an oil-rich soup in the carb bowls. If you're lucky enough to get the motor started, it smokes everybody out at the ramp. On other motors, okay if you feel the need. But you really don't have to worry about a few days or even several weeks. If we're talking months...

 

[jtexas]

Re: Run Engine out of gas before leaving dock?

Reasons I don't:<br />1. can't power load with no fuel<br />2. sit on the ramp running the engine with people waiting? no thanks<br />3. top cylinder goes lean while #2 & 3 keep banging away, no gas = no oil, no thanks. (premix)<br />4. if I don't use my boat within 3 or 4 weeks, it's because of some bad luck or emergency and not something I know about today. If 5 weeks goes by without I go fishing, I put the muffs on & crank her up.

 

[boatster]

Re: Run Engine out of gas before leaving dock?

With my Tohatsu 2 stroke the oil injection system puts the oil in after the carbs. So I don't think it would really wear that much. I usually run the engine out after every use. I'm very curious to see what the overall consensus is though. I don't proclaim to know if I'm doing my engine good or bad. I can see how running it lean might increase heat and maybe eventually damage something, but for a minute or two?

 

[LubeDude]

Re: Run Engine out of gas before leaving dock?

First three boats I owned, I ran the fuel out after trailering. Small lakes and didnt hold anyone up. Dont think I caused any damage?????<br /><br />Now with my 150 Merc and hanging out here, I dont anymore. If I am not going to use the boat for a few weeks, I just go out every now and then and pump the bulb hard keeping the carbs full. My main reason is that I dont want the gaskets drying out let alone having the fuel dry up in them. So far so good. I have never used a fuel stablizer and my boats sit for about 4-5 months of the year.

 

[JasonJ]

Re: Run Engine out of gas before leaving dock?

When it gets close to the end of the season I toss some Stabil in the tank and not worry about it. Besides, on my motor anyway, the gas dribbles out of the bowls when the motor is tilted. I do think I'll pull my carbs this winter, I have not rebuilt them as long as I have had this motor, it has always ran good and I never saw the need. I'll just be doing it as preventive maintenance so I don't have to worry about it next season.

 

[rodbolt]

Re: Run Engine out of gas before leaving dock?

problem is the fuel pick is normally through the main jet. once it quits there is still 1/4 inch or so of fuel to clog things. meaning there is no sense in running it dry cause it still does not drain the carbs. some carb desins are more tolerant than others of main jet clogging.

 

[cobra 3.0]

Re: Run Engine out of gas before leaving dock?

I carry my 15hp 2 stroke in the car on its side and that's why I always run it dry. However, if you want to be safe, I wouldn't bother to run it dry if you are going to reuse it in a few weeks(even within a couple of months). Varnish takes many months to produce (usually over winter)not weeks.

 

[PistlePeat]

Re: Run Engine out of gas before leaving dock?

Since 1968 I have owned approximately 10 outboard motors, from 10 to 75 hp. Most all were OMC, but 1 was a Merc. None were oil injection. I have run them dry every single time unless I leave the boat in the water on vacation and expect to go out the next day. Three of them I still own - a '73, a '83 and a '70. They all are in perfect condition and I have never done any service to any of them except change the oil, fuel filter, tune-up, etc. I do the same with my lawnmower over winter. My father leaves his mower full of gas with stabil and has has a few carb problems over the years. I think I'll stick with my method since it works for me.

 

[jy118lfd]

Re: Run Engine out of gas before leaving dock?

I have a 83 150 crossflow and when I tilt the motor up it drains most of the gas out all by itself all over the splashwell unless I put a rag or something in there so I geuss I get the best of both worlds a lubricated floor and little gas in the carbs

 

[burnboyy]

Re: Run Engine out of gas before leaving dock?

I can't speak for the carbs, but most gasket materials do have a tendancy to shrink/swell when wet or dry. This swelling could be such a small amount it can't even be seen, but as the seals get wet/dry over a long period of time it could cause leaks, the motor was designed to have fuel in it's lines, and acording to "Seloc" manuals a motor should be run every few months regardless of fuel stabilizer etc, best bet i think is use fuel stabilizer, leave fuel in lines when done but disconnect fuel tank so you dont end up with a flooded motor or hard start, and most importantly run your motor atleast every 4 months, if running a motor less then 3 times a year might as well rent a boat or pay a charter anyway

 

[Chris1956]

Re: Run Engine out of gas before leaving dock?

I used to run outboards on six gallon portable tanks wit 50::1 premix. These ran dry at least once a day, usually at cruising speed. Never had any damage from this practice. Why would running your carbs dry at idle be worse?