Run the outboard dry

dlewis812

dlewis812

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May 21, 2006
321
catalina 25, 30 montauk / manhattan
Yet another "should I run the gas out". I used to always run the gas out however after reading he many threads seemed like not a good idea. That was when I sailed frequently however now hardly ever. Most likely won't be at the boat for about 6 weeks, maybe run it out? (I did not put in any additive). Honda 8HP 4stroke

Thanks!
 
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Chief RA

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Nov 26, 2012
2,315
Catalina 250 Bodega Bay CA
I think most of us don't even want to touch this as it is very controversial. Do put what is most recommended here in your gas and that is seafoam additive. With this you should not need to drain your carb over a 6 week span. I personally do drain my outboards for winter storage but many do not if they have a good additive added. Its your call.

Chief
 
Gunni

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Run the gas out, open the carb drain screw and dry out the bowl. Take the fuel tank and dump it in your auto. Take the fuel line apart and drain the fuel. Unless you want to be rebuilding/replacing your carburetor. :)
 
kloudie1

kloudie1

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Nov 6, 2006
9,892
Hunter 34 Mandeville Louisiana
Yup.. If you can get some non ethanol gasoline to use.. put in some Stabil and a detergent of your choice, like Seafoam.. you'll be miles ahead!
Looks like you don't have a convenient place to buy non-ethanol fuel, but there is always the airport.. If there is a small airfield nearby, you may be able to buy some avgas for the boat. It will be ethanol free.

EDIT.. Hondas generally have a convenient bowl drain screw . You can hold a cup under the drain hose and drain it then put that back in the tank.
http://pure-gas.org/
 
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Ron20324

Ron20324

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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I dunno... My opinion is if you drain the gas, there is a film (like buttemilk in a glass) of it that will evaporate, leaving a film on the inside of the carb. Don't ask what film, like a lacquer? My 2 cents.

I bought a tank of gas at the airport last year, and IIRC there was a sign that it had lead in it, and wouldn't put that in a car engine. Supposedly that lead would ruin the catalytic converter.
 
Don S/V ILLusion

Don S/V ILLusion

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Sep 25, 2008
7,096
Alden 50 Sarasota, Florida
Gunni said:
Run the gas out, open the carb drain screw and dry out the bowl. Take the fuel tank and dump it in your auto. Take the fuel line apart and drain the fuel. Unless you want to be rebuilding/replacing your carburetor. :)
Click to expand
That's certainly one extreme. A more prudent approach is as others suggested. Use non ethanol gas sometimes sold as av-gas and put the recommended stabilizer in it. Six weeks is not long enough by a long shot to do anything onerous.
 
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Crazy Dave Condon

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Jun 8, 2004
10,060
-na -NA Anywhere USA
Over the years with pure gas or gas/ethanol, many tend to forget that gas is an oil by product. The Carburetor has many fine ports in it and if clogged, that will interefer with the engine thus taking the carb off an outboard and cleaning it. There are many carb cleaners but over the years 2+2 was the best for me cleaning taking it apart to clean to include the fine ports or jets as some would say. Put it back together without changing any settings and generally started up on the first pull running well.

Additives are fine especially for the ethanol but if leaving the boat for several days or more and in the winter, I would simply shut the gas supply off and let the engine run out of gas. Yes you will have to pump some in which does not take long but at least no gas is left in those fine ports/jets to have gas to coagulate and block them . Too many of my customers followed my advice and never had issues with the engines for years.

At the end of the season, take the fuel remaining in the gas tank, remove it and dispose of it. I would use it in my car. Gas does become bad over the winter which is not good to be left in the engine and gas tank. It is easy and called regular maintenance
 
sailaway78

sailaway78

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May 11, 2005
3,431
Seidelman S37 Slidell, La.
Run it dry

Here is one of the few times I agree with gunni. Run it dry, unless you can get non ethanol fuel. And even then if it's going to sit for a long time, run it dry. Any thing else you do is asking for problems. What many don't understand about ethanol. The alcohol absorbs moisture. Up until it gets saturated, then the water drops out, and settles in the bottom of the tank or bowl. And this is just one of the problems it poses. Follow gunni's advice and get it all out of there every time.
 
Brian S

Brian S

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Nov 9, 2012
2,500
Oday 192 Lake Nockamixon
I went to a local private airport, and inquired about buying ethanol free to the guy at the front desk. Probably not the best person to ask. He thought they would not sell to me because of "highway taxes." In my opinion, highway taxes wouldn't apply to my lawn mower, my boat outboard, etc.

When I'm using my motor at least once every other week, I don't think it's got enough time to evaporate out of the carb bowl, or to oxidize too heavily. I also use ethanol free, Sta-bil and Seafoam. If I was going to let her sit for a month, I run the bowl out. When I winterize, I definitely drain the bowl with the drain port, and pour the excess fuel into the car.
 
Ken Cross

Ken Cross

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Oct 24, 2010
2,405
Hunter 30 Everett, WA
Since you have a 4 stroke

4 stroke engines don't suffer from lubrication issues like if you ran a 2 stroke out of fuel.
Really for just 6 weeks, I'd just run the carb out of fuel. This can be done by draining the carb, disconnecting the tank and running it dry, or in the case of my tiny 2 hp, shut off the fuel valve and run it dry. Tiny ammounts of deposits left after the carb is empty should flush away once fuel is flowing again.

I've had great luck with this procedure, but the minuite I forget, I'm dissassembling and cleaning the carb again. That's why I use ethanol free fuel any time I can.

Ken
 
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Chief RA

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Nov 26, 2012
2,315
Catalina 250 Bodega Bay CA
Ken: 2 strokes suffer no ill effects when fuel is run out. The lubricant is in the fuel, how can it not be lubed to the last drop? Chief
 
Brian S

Brian S

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Nov 9, 2012
2,500
Oday 192 Lake Nockamixon
Chief RA said:
Ken: 2 strokes suffe no ill effects when fuel is run out. The lubricant is in the fuel, how can it not be lubed to the last drop? Chief
Click to expand
What I have read is that as you get to the end of the fuel, the mixture becomes very fuel (and lubricant) lean, and that's where the problem is. That last 30-45 seconds when it starts running faster even though you haven't touched the throttle

Never seemed to be a problem on Granddad's boatallthose
 
Brian S

Brian S

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Nov 9, 2012
2,500
Oday 192 Lake Nockamixon
Brian S said:
What I have read is that as you get to the end of the fuel, the mixture becomes very fuel (and lubricant) lean, and that's where the problem is. That last 30-45 seconds when it starts running faster even though you haven't touched the throttle Never seemed to be a problem on Granddad's boatallthose
Click to expand
Problem on Granddad's boat all those years.
 
Brian S

Brian S

.
Nov 9, 2012
2,500
Oday 192 Lake Nockamixon
Brian S said:
What I have read is that as you get to the end of the fuel, the mixture becomes very fuel (and lubricant) lean, and that's where the problem is. That last 30-45 seconds when it starts running faster even though you haven't touched the throttle Never seemed to be a problem on Granddad's boatallthose
Click to expand
Boat all those years.
 
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Chief RA

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Nov 26, 2012
2,315
Catalina 250 Bodega Bay CA
The cylinders do not scrub clean with the last few seconds of run. The oil tends to remain on the cylinder walls for some time. The oil viscosity and adhesion for 2 strokes is designed that way. You were taught wrong. Chief
 
Ken Cross

Ken Cross

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Oct 24, 2010
2,405
Hunter 30 Everett, WA
Chief RA said:
Ken: 2 strokes suffer no ill effects when fuel is run out. The lubricant is in the fuel, how can it not be lubed to the last drop? Chief
Click to expand
That makes sense. I knew it would be okay with the 4 stroke.
Ken
 
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Chief RA

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Nov 26, 2012
2,315
Catalina 250 Bodega Bay CA
Ron: There is virtually no film left in a carburetor when it is drained. Pour some gas in a glass container and then pour it all out. Let it sit until remaining gas is evaporated and check for residue. If you leave a quantity of gas in the container and let it evaporate you will get the film you allude to. Thats what happens to a carburetor left with gas in it until it evaporates. Chief
 
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CarlN

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Jan 4, 2009
603
Ketch 55 Bristol, RI
If you are really only going through a few gallons of dinghy gas a year, one strategy is to buy "small engine fuel" (be sure to get the 4 cycle version with no oil mixed in). This has no ethanol and stabilizers already mixed in. It will last a long time. My Honda dealer (who sold me some) said the 93 octane is fine as long as I don't run for long periods at wide open throttle. No need to run it out. I got it from my Honda dealer (they sell a lot for landscaping equipment). Home Depot sells it too.

http://www.homedepot.com/p/Unbrande...-94-Octane-Ethanol-Free-8-Pack-6208/203528942
 
caguy

caguy

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Sep 22, 2006
4,004
Catalina, Luger C-27, Adventure 30 Marina del Rey
Most of the old power boater salts at the ramp flush the motor out with fresh water while running the carb dry.
 
thinwater

thinwater

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Mar 26, 2011
3,414
Corsair F-24 MK I Deale, MD
The only carbs I ever had to work on were those the PO ran dry. In 30 years (much of it with 2-3 outboards--catamarans and dingies), I have NEVER run a carb dry and have never clogged a carb. I've never worried about e-10.

I do run a good corrosion inhibitor (Merc), since I've seen bowls pit, and the aluminum oxide has to go somewhere. I have a suspicion it does far more harm than gum (gum dissolves in fresh gas, aluminum oxide does not).

I've got a sneaking suspicion that this has no provable answer, since even manufacturer manuals differ.

Enjoy your controversy.
 
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