you will probably get different answers on this.

Even if you run the engine until it quits, there is still residual fuel in the carburetor and probably the fuel tank. When ethanol fuel is used, the alcohol will seperate from the gasoline and combine with moisture from the atmosphere or condensation. This is likely to damage or corrode the carburetor.

You are always better off when fuel preserver is used.

Ethanol probably changed the game. My thoughts are these: If the fuel tank doesn't have a shut-off valve, fuel in the carb will evaporate and more fuel will continuously enter the bowl and eventually varnish will occur. If the shut-off is used, the fuel in the bowl will evaporate and no varnish will form.

If there is no shut-off, and I think every unit should have one and it should be used, I would drain the system and I don't think there will be a problem. That's what I do.

Adding Sea Foam to the fuel on the last trip, and then draining the system, would be the best.

My 2 cents on the matter.

I've been using this procedure for over 35 years and NEVER has my equipment failed to start in the spring. That includes ethanol mixed gas.

I plan to have as little gas in the tank as possible, I then let the engine run dry, as it starts to sputter, I engage the choke which lets it run a bit longer and removes even more fuel from the carb bowl. I then remove the fuel hose from the carb (with or without shut off) and let whatever fuel is left in the tank empty out. There will always be a bit left in the tank. Sometimes I even attach my compressor to the tank and blow out whatever is left.

Next I remove the spark plug and shoot a little oil down the cylinder and pull the chord several times. I then slowly pull the chord until I feel resistance and stop, the cylinder is now at Top Dead Center and that relieves the pressure on the valves springs as well as sealing the cylinder a to prevent moisture buildup.

Lastly I change the oil, clean or replace air filter and spark plug, then screw the spark plug back in hand tight.
I also install a sharpened blade ((spare) at this time.

In the spring I unscrew the spark plug, pull the chord several times to purge the cylinder of oil, screw the plug back in and add fresh gas (with Stabil). I pull the chord once or twice and the engines always start right up,
It may smoke for a little while since some oil still remains in the cylinder but clears up shortly.

My recent push mower, a Toro Personal Pace is going into it's 14th season and still always starts in the spring, as well as all summer on the first pull. All my equipment is stored in unheated shed and out of the elements.

There are many who believe top off the tank with Stabil enriched gas is a better method, however, this method has worked for me all these years and I intend to continue.

In my business, the non-starters almost always have fuel in the tank. Sometimes, it's been treated with Stabil.

Just like itzbinnice, I empty the fuel in my stuff. Running it till it stalls has been good enough for me since 1976.

Sea Foam is available at Auto Zone or similar auto stores.

It's even more simple. Use Sta-Bil in your gas can every time you fill it. Then you don't have to do anything special concerning the fuel at storage time, but common sense should tell you that unless you have a fuel shut-off and use it, you should run the mower out of gas to prevent a leakdown into the engine and crankcase during storage. Plus, the mower fuel system vents, so it will gas-off volatiles and lose it's octane rating if you leave it full of fuel for an extended period. Fuel stabilizer cannot prevent that but it's still worth using. Use the Sta-Bil for alcohol-blended gas if you use that - it's a super concentrate and is blue.

I use Stabil with every tank, at the end of the season, I fill the tank to max capacity. I start the motors 2-3 times during winter to circulate the fluids a bit. I use the blue stabil for 2 cycle and the pink for 4 cycle. I also add 2 oz/gallon of Lucas fuel conditioner. This helps keep the combustion chamber and valves free of oxidation. If you empty the tank, you will get condensation in the tank and other areas.

Although I run my equipment dry,I still use Stabil all year
in my outdoor equipment.

Regarding my Snow Blower, another reason why I run my equipmentment dry.

In the early spring I run my Snow Blower dry and store it.
Last winter was a mild one so I never had to use it.
Had I topped off the fuel with Stabil, that gas would have remained in the tank for two years. The label on the Stabilizer states storage life is 1 year. I only put gas in when I intend to use the snow blower thus not subject to have gas remaining there over 1 year. It would be a waste of gas and time to have to drain the tank if I never used it in a winter season.

For those in harsher climates that AlWAYS get snow, this reasoning wouldn't apply to you.

That is why I have since Stopped buying Stabil and used as an alternare for both Stabil and Lucas Top end Conditioner I utilize Star*tron for both purposes , Star*tron will stabilze Fuel up to 2 yrs in storage. Available within Walmart and Napa Stores . Great Product especially with E Fuels or Diesel applications. Note: I agree that fuel line shutoff valve is very important Safety Device.

I always buy non-ethanol fuel for my small engine tools and my motorcycle(Union76/conoco philips etc.) The ethanol problem might get worse - 15% in the future.

Happy New Year. I used to use stabil. Now, I just mix in a dash of MMO with every tank of fuel. My 4 strokes all have shut offs and I run the carb dry after every use. I have gotten better fixing Tecumseh carbs than I ever wanted to. My walk behind is a freebie I rescued in '09. All it needed was a shoulder bolt for a hgt adjuster. It is a Toro 21" 3 speed with a Suzuki GTS 4 stroke. It still starts on the first pull. And ,ya know what, when it doesn't, I will fix it 'til it does.