Preventing fuel tank corrosion
 

Having seen a few threads about leaky/rusty gas tanks I just figured that I'd throw this out there for anyone that maybe hadn't heard it before. Putting just a splash of two-stroke oil in your fuel can help to prevent corrosion. I'm not talking about mixing it 40:1 or any particular ratio for that matter. About a quart jug capful of oil to a full tank of fuel is plenty. If you were to bother to figure out the ratio it'd be probably be more than 1000:1. If you do want to bother to figure a ratio, I wouldn't go any more than 500:1 for gas you're going to use in a four-stroke engine. Just enough that it leaves the tiniest bit of an oily film anywhere it comes in contact. It won't hurt a thing at that small concentration and will lube the internal carburetor parts and even ever so slightly improve valve stem lubrication and piston ring sealing. Any old cheap Walmart universal two- stoke oil will do, or any other brand you happen to have around for two-stroke bikes, or your weed-eater, leaf-blower, etc. Like I mentioned, just don't go overboard and pour already mixed two-stroke gas, or some big quantity of oil, in your tank. Just a splash of oil in plain gas is all you want.

Yep, MMO also works well. Bonus side effect - prevents wear on carb parts and the face of the valves against the seat too. I prefer the MMO as it burns cleaner and helps break up carbon deposits and prevents them from sticking.

Sta-bil works great. Use a little every fill up. Use a heavy dosage when storing for the winter with the tank95%+ full

Never use sta-bil,it turns to jell after setting all winter.

I have used Sta-bil for decades in everything from lawn mowers to stored autos and use it every year in 4 motorbikes.

It does not jell over a winter.

In fact, raw gas will not jell over a winter. It might clog in the tiny passages in our miniature carbs but the tank/lines will not jell.

My weed eaters and chain saws get only the 2-stroke oil in the fuel and they do fine after months in storage.

During the pandemic I stored a vehicle for two full years with only raw E-10 in the tank and it fired up after a battery jump with no "jell" complications. After that I completely stopped worrying about fuel stored in gas tanks, jugs or bleach bottles. If it don't stink use it.

I did a 2 stroke oil in gas test on my Honda Rebel 250 a few years ago, and the ideal ratio is between 1:100 and 1:300, with 1:128 being the easiest one due to one gallon of fuel needing one oz of oil, and around 1:150-1:200 being the ideal ratio to have some of that upper piston lubrication, while at the same time not polluting the exhaust.

Once you hit 1:300 ratios, the effect is pretty much non-existent.

What mixing 2 stroke oil does to your bike engine, is run it cooler and smoother.

It drove my mechanic crazy, because he could see traces of oil on the piston head.
I just told him I had bought a fuel stabilizer, and that probably was the reason.

At a 1:100 ratio or below, you kind of start clogging and fouling the exhaust.

2 stroke oil completely mixes with fuel, so I doubt it does anything to corrosion. As soon as you fuel up a new tank, the new fuel will dilute and wash away any remnants of oil in the tank.

I guess I should have stated to add it to every tankful to be more clear. As far as the ratio, My thinking is that some is better than none.

MMO recommendation is 1/2 ounce per gallon. I usually go 1 ounce, but the effect is the same as 2 stroke oil. You just get a lovely minty smell to your exhaust. If you don't have a cat, you don't really need to worry about going heavier, other than carbon buildup.

While both oils do mix with the fuel, they do not fully integrate, so they still leave behind a bit of a film to protect the bare steel in the tank.

My main reason for liking MMO over 2 stroke oil is that it mixes more readily with gasoline and stays suspended. 2 stroke oil does eventually settle out of fuel if you let it sit. At very thin mix ratios it's not really an issue though.

As far as Stabil. It doesn't cause gelling as far as I am aware. I had a gas can sit with ethanol free fuel and Marine stabil that I forgot existed for almost 2 years and the gas was still perfectly fine.