'Fresh' Gas in Outboard?

[Sluce]

Three years ago we bought a Tohatsu 2hp 4-stroke outboard. After the sale, and a $230 bill to clean the carborator, the dealer told us you always had to use fresh-bought gasoline and never use gas over a month old. This is rather difficult, as we don't use the outboard ofter early or late in the season, and it appears we would need to run the engine dry if we don't intend to use it again for a few weeks.
How do others handle this situation? Is the dealer being overly cautious? Are there other small outboards that require less babying?

[Vasco]

I think it's hogwash but if you're worried put a bit of Stabil in your gas. I use gas that's more than 6 months old in my Yamaha. And if I got charged $230 to clean a carburetor I'd never go back to that dealer again.

[Eric M]

The lower the HP of an outboard, the smaller the passages in the carb.
The longer fuel sits in these passages the more likely they will get clogged. Leave the fuel for a day and probably 1 in ten million times you will have a problem. Leave fuel for a year and it is probably close to a guaranteed problem.
The age of the fuel is a secondary issue compared with how long you have left it in the carb. I have a 2HP 4 stroke Honda and if I am not going to run the motor for a few weeks I shut off the fuel line and run the gas out of the carb. Few week old fuel should run fine the next time you use the motor, but I will say that I have switched out 3 month old fuel to new fuel and found the motor to run much better.

--Eric

[mesquaukee]

You were taken advantage of. Cleaning a carb is a straightforward task. I would suggest you learn how. Most of them are made for easy disassembly without needing gaskets and rebuild kits.
As for month old gas being no good hogwash. We have stocked up on gas and used it for up to 3-4 months in the tropics before we replenish. We have a 4 stroke Yamaha. 4 strokes are pickier about the cleanliness of the fuel and do not tolerate water well. There are a number of very small passageways in a 4 strokes carb that do not exist in a 2 strokes carb. They need to be kept clean, easy to do with a few fine strands of copper wire
There should be a drain fitting on the carburetor, it is either a screw or bolt. If you leave it for more than a few weeks, run the engine, stop it, open the drain, empty it, run the engine.

[hellosailor]

Pump gas is designed to remain good for 60-90 days from the time it leaes the pipeline or depot. Ask any gas company about their product.

It is a witches' brew of about 60 chemicals inclduing heptane and butane which boiul out as gasses at room temperature and are soon gone.

Yes, it can usually be used longer than that, but the best answer is to add in Sta-Bil or something similar if you want to keep it longer. Or, with the price of Sta-Bil, just dump the gasoline in your car and replace it sooner.

As gasoline breaks down it forms gums and varnish--just like paint varnish--and there's magic way to undo that, except by tearing things down and rebuilding them.

[LakeSuperior]

I always run a little bit of carb cleaner in the fuel full time to discourage any gum formation in the carb. Also, run all three of my outboards out of fuel before I store for the winter.

My 15 horse Honda carb uses O-ring gaskets and is made to come apart and be cleaned. It takes 10 minutes (after the 1st time).

[Strygaldwir]

Since you have a four stroke, you can dump the gas into you car. I do that at the end of the season. I started doing this because when I bought a new dinghy I transfered my motor. The engine was only three years old, but I hadn't run it for 8 months. When we transferred it, both I, and the dealer, noticed how rough it was running. He offered to "fix" it for me for $175. Having paid $4k for the dinghy, he was fairly sure he had a sucker on the line. Well, having built MANY engines in my time, I declined. I disassembled and cleaned the carb and changed the plugs. It still ran rough! I looking into the tank. Hmmm....!!! There's water in there!? How'd that happen??? Dumped the old fuel, put in new, after running for 5 minutes, it purrs like a kitten. So, Now, I regularly look into the tank and I'll run the fuel out the engine by disconnecting the tank and letting the engine die from fuel starvation. No worries at that point.

[thinwater]

Originally Posted by Sluce

Three years ago we bought a Tohatsu 2hp 4-stroke outboard. After the sale, and a $230 bill to clean the carborator, the dealer told us you always had to use fresh-bought gasoline and never use gas over a month old. This is rather difficult, as we don't use the outboard ofter early or late in the season, and it appears we would need to run the engine dry if we don't intend to use it again for a few weeks.
How do others handle this situation? Is the dealer being overly cautious? Are there other small outboards that require less babying?

Which means filling the tank AFTER use, not before. very easy.

This will also prevent water absorption, which treatments will not help.

[Cheechako]

Run it dry if it's going to sit over 3 months. There should be a bleed screw on the bottom of the carbureator. Geez $230 for a 2 hp tohatsu???? You didnt pay more than double that for the engine did you?

[TOHATSU GURU]

Most shops charge for one hour labor, on an engine of that size, to clean the carb. Correctly cleaning it involves taking it apart and soaking the body and metal bits in carburetor cleaner for three hours. Fuel should generally NOT be stored for more than 30 days in a marine environment if possible. On a small engine like this one, with a tiny fuel tank, you are much better off finding another use for the fuel rather than letting it sit where it can absorb water, become contaminated with foreign matter or destabilize. The dealer was dishonest if they charged that much for a carb cleaning and if you would like to avoid getting gouged in the future your best course of action is to run the fuel out of the engine each time you are done using the engine for the day. Everyone intends to use the engine tomorrow or next week, but things come up and next week turns into next month which turns into 6 months or longer. Be proactive and prevent the problem from occurring in the first place.

[thinwater]

Originally Posted by thinwater

Which means filling the tank AFTER use, not before. very easy.

This will also prevent water absorption, which treatments will not help.

First, every time you add even a little fresh gas you replenish the anti-oxidation additives enough to get you a few more months.

I never close the line from the tank to the engine. That way the carb stays full.

In 30 years of boating I have NEVER had a carb issue.... Except when I bought a new boat where the PO had drained the engine and dsiconnected the line each time. Had the clean the carbs (2, very easy, it's true, just like my first car) and replace the hose end fittings from pointless wear.

* Full tank.
* Top-off after every trip.
* Never leave an engine idle for more than a month if possible. Just run it a little.
* Leave hoses on.
* Sailors, run the engines a little more. You won't wear it out in most cases. It will be age. Cruisers, you run plenty.

[MarkJ]

Originally Posted by Sluce

we don't use the outboard ofter early or late in the season,

Just go cruising.

Fuel never sits in the outboard. The Dink is like the family car with the engine never getting a chance to cool.

And the longest passage of about 3 weeks keeps the fuel inside sloshing around.

Come to think of it, the poor old OB gets a miserable life cruising! Sitting on the back deck rail (pushpit to you nautical types) in bad weather o having the engine gunned all day only to be switched off when the prop hits the sand.......





Mark

[TexSail]

I use Stabil if the gas will be in the tank more than two months. I also use a half pint of mineral spirits per 6 gallon tank twice a year to keep the varnish out of the fuel system. The engines are old but run like a top.

[SkiprJohn]

Here in Hawaii on the Big Island, Hilo side, there is only one station that sells gas without ethanol. Leaving ethanol gas in a small tank or carb will eat away or harden to brittle any pickup tubes. It will also eat away at polyester fiber tanks and create a jell that will not work in your engine.

I run all the gas out of the carb each time I use outboard, pressure washer,chainsaw weedwhacker. I've experience and seen so many problems caused by this junk that I don't want to use it. Stabil will help but left in an outboard for any length of time will not be good.
The auto and truck use it so fast that it is not a problem.
Good luck.
Kind regards,
JohnL

[David M]

The newer gas with the much higher alcohol content does cause carburetor clogging. We tried using fuel stabilizer specifically formulated for gas with alcohol and it failed to keep the carburetor clean on one of our boats at work...a carbureted Yamaha 80 four-stroke only a few years old.

The solution I found is to run all the gasoline out of the carburetor before putting the outboard to bed. Also, gas will last longer if you keep it stored in a vapor tight container. Once the lighter stuff starts evaporating away, the heavier more concentrated stuff left behind is what is going to clog your carburetor.