Running gas out of carbs for winter and / or long term storage

[JDusza]

Got some feedback on this that surprises me. I would appreciate more detail.

I am used to running the carburetors out of gas before storage to minimize them getting gummed up, or if they do they get gummy, they would do so with the float and needle down, in the open position. I do this by disconnecting the fuel line at the motor.

Some have recommended not doing this on multiple carburetor systems because one of the carburetors will go empty before the others and this will strain those cylinder(s) that are run out first, not to mention totally damaging them.

I can understand the theory, one of them will go out first, but, I interpret what is said as running the engine out of gas can totally ruin the block. These words are pretty strong. I do not understand. Removing the gas line simply simulates the gas tank running empty. This happens everyday. An engine that doesn't start because of no fuel isn't ruined by cranking the starter. An engine that doesn't start in the spring isn't ruined.

Why would I expect to ruin the engine if the tank runs out of gas?

If this were true, there would certainly be no outboard market and we would all have sailboats; that is, unless the mast and boom go bad when there's no wind. lol

What's up with this? Why the strong words not to run out the carbs? Is this damage something that happens on newer models made of cheap materials or any other cost limiting design factors?

Who would buy an engine that blows cylinders if it simply runs out of gas?

Thanks. Just trying to understand,
J

 

[HighTrim]

Re: Running gas out of carbs for winter and / or long term storage

You are forgetting the most important thing. A 2 stroke motor gets it lubrication for the pistons/cylinders/etc from the oil, which is in the fuel. It is not the fuel per se that you are worried about running without, it is the oil.

Do not run a multi carb motor dry. It is an expensive lesson. Simply add Marine Stabilizer such as Stabil, run the motor for 10 minutes or so to get the fuel into the system, fog her until she dies.

 

[wilde1j]

Re: Running gas out of carbs for winter and / or long term storage

I disagree. I ran my '85 J 140 out of gas after every use, when it wasn't going to run again within two days. When I sold it in 2004, it had over 800 hours and compression was still over 130 psig all around. In my view, this is just an old wives tale. There are certainly lots on both sides of this topic. I've run many motors dry over the years, never with any adverse effects. I should note, that you would NEVER do this with any of the DI motors, however, but for entirely different reasons.

 

[1946Zephyr]

Re: Running gas out of carbs for winter and / or long term storage

For winterization, I would just drain the carbs, by removing the drain plug on the bottom.

 

[JDusza]

Re: Running gas out of carbs for winter and / or long term storage

Thank you, everyone. This is all very good input.
J

 

[nwcove]

Re: Running gas out of carbs for winter and / or long term storage

this topic has been beaten to death.....so another point wont hurt.
if you lean a two stroke out for a few seconds , running it dry, it wont cause immediate damage, but it cant be good for it. its just causing wear and tear that doesnt need to happen.

 

[wilde1j]

Re: Running gas out of carbs for winter and / or long term storage

The flaw in your logic is the oil on bearings and cylinder bores doesn't disappear instantly when fuel flow stops. Otherwise I would have smoked mucho motors, and that never happened.

 

[boobie]

Re: Running gas out of carbs for winter and / or long term storage

Has anybody ever looked up the storage/fogging mix recommended in the OMC/BRP factory service manuals and used their procedure?? I've used in both carbed and DI mtrs and never had a problem. E-TEC is a little different.

 

[JimS123]

Re: Running gas out of carbs for winter and / or long term storage

The flaw in your logic is the oil on bearings and cylinder bores doesn't disappear instantly when fuel flow stops. Otherwise I would have smoked mucho motors, and that never happened.

Bingo!!!

Grandpa always told me to run the carbs dry after each use. I've been doing that for 45 years with single, dual and triple carb motors. EVERY single outing.

The only thing I leaned here was that tweaking the choke at the end will get a bit more out. Grandpa never told me that.

StaBil the tank before the last outing, so that if any remains will be stabilled.

 

[JimS123]

Re: Running gas out of carbs for winter and / or long term storage

Has anybody ever looked up the storage/fogging mix recommended in the OMC/BRP factory service manuals and used their procedure?? I've used in both carbed and DI mtrs and never had a problem. E-TEC is a little different.

I have factory manuals for OMC engines that I bought new between the years 1964 and 1984. They ALL say the same thing....
* put 1 oz/gal OMC 2+4 fuel conditioner in the gas tank (their version of StaBil.)
* run the motor to operating temp, disconnect the fuel line and squirt fogging oil in the carb and / or fogging port until the motor runs out of gas.
* Keep upright so the water drains.

So, fuel going bad was known many years ago...Stabil is nothing new......and the factory didn't think running the carb dry would hurt the internals...

 

[boobie]

Re: Running gas out of carbs for winter and / or long term storage

I think you should find some newer manuals. Something from 1995 and up. '98 especially. Lot different procedure than yours. And yes, I know about the "64 to '84 manuals.

 

[1946Zephyr]

Re: Running gas out of carbs for winter and / or long term storage

During the boating season, I just unplug the fuel line and shut 'er down the first time it misses. Always worked well for me. For storage, I just drain the carb out completely. I have never used stabil and don't feel a need to.

 

[gjmsd]

Re: Running gas out of carbs for winter and / or long term storage

We have a different procedure here in San Diego. We just use our boats year round.

 

[1946Zephyr]

Re: Running gas out of carbs for winter and / or long term storage

Yea, winters are a bit nicer down there than what we get. LOL

 

[5150abf]

Re: Running gas out of carbs for winter and / or long term storage

What si the logic to draining the carbs after every single use, I have never understood it.

Is there an actual reason besides "Grampa told me too", I am sure grampa had a good reason but what was it.

I drain my carbs at the end of the season thru the drain plug and that is the only time all year.

 

[JimS123]

Re: Running gas out of carbs for winter and / or long term storage

I think you should find some newer manuals. Something from 1995 and up. '98 especially. Lot different procedure than yours. And yes, I know about the "64 to '84 manuals.

My motors are 64-84. If i had a '98 I'd have a '98 manual.

So, please tell us what the lot different procedure is. And, does that apply to '98 motors, or does it supercede the previous manuals as well?

 

[JimS123]

Re: Running gas out of carbs for winter and / or long term storage

What si the logic to draining the carbs after every single use, I have never understood it.

Is there an actual reason besides "Grampa told me too", I am sure grampa had a good reason but what was it.

I drain my carbs at the end of the season thru the drain plug and that is the only time all year.

In the old days straight 30w oil didn't blend in as well as modern TCW's do. It was felt (rightly or wrongly) that separation would occur. Back then many boaters shook their portable tanks more than just when they filled them. So, the thought was that a blend in the carb might separate. Of course, don't forget we were running 16:1 as well.

The point of my statement was to emphasize that pulling the plug won't burn up your pistons. Also, it wasn't just Grandpa, the marina I bought all my new motors from back in the 1950's and 1960's recommended it as well.

Finally, if you take the OB off and lay her down in the trunk of your car to go home, runnin her dry is the only smart thing to do.

 

[sschefer]

Re: Running gas out of carbs for winter and / or long term storage

Run them dry or not. Well here I go... Run them dry on a portable that you're hauling around just for safety --- Yep, I'd do that. Run them dry at then end of each use - Nah, I'd just run StaBil in my gas. Run them dry at the end of a season - Nah, I just fill the tank to the top add a double dose of StaBil, run it for 5 minutes, fog it and store it.

Will running it out of gas hurt a multi-carb engine, yes, at 6,000 RPM a lean-out will probably burn a pistion. At idle, nah, it'll just run out of gas. Will you run out of lube in the bearings - nah, there's plenty of excess.

With my 4 stroke injected motor I only plan to change the lower unit lube, tilt it down to drain out any water, fill the tank, add a double dose of StaBil, run it for 5 minutes or so and then put it away for a couple of months.

 

[boobie]

Re: Running gas out of carbs for winter and / or long term storage

Jims123, I think this newer procedure supercedes the older ones. I'd put it on here but it's to long to type out. Go down to a local BRP dlr and have him show you storeage procedures from a newer service manual. Anyway I've had good luck with it.

 

[emdsapmgr]

Re: Running gas out of carbs for winter and / or long term storage

If your 2 stroke engine has a VRO mixing fuel pump, you can have problems if you pull the fuel line at the end of the season for winterizing. When the fuel line is pulled, the oil line is not. As the engine continues to run, it will pump more and more oil into the carb bowls. You will have a hard time starting an engine which has oil in the carbs next spring. After you have fogged the engine, unscrew the carb bowl drains and let the fuel drain onto a towel.