Gas octane rating for mowers?

I use the same gas that goes in my cars in boats, yard equipment, collector cars, motorcycles, atvs you name it. Been doing that as long as they started adding them and not one issue related to oxygenated fuels. I read all the concerns about seals and rubber degrading just never saw it in anything I own. Of course I’ve also been doing 7-10k oil changes for decades too. Must be charmed…

No, I was using regular alcohol-gas, ate up the carburetor and fuel lines. My 2stroke boat motor was built prior to alcohol-gas too.
I do use the canned pre-mix in my weed whacker though, but when it dies make go electric for that.

I think he could have advanced the ignition timing a little to compensate for the high octane fuel’s slower flame progression. If you want to see a red-hot exhaust manifold, just retard the ignition timing.
Something similar happens when cruising in cars where the exhaust gas recirculation is active. The engine needs extra spark advance to offset the slower flame propagation of the exhaust diluted fuel air mix and if the EGR valve is stuck closed, you get detonation at cruise speeds, detonation that goes away if you floor the gas pedal and run the engine at a power setting where the EGR is closed anyway.

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If you’re talking about small engines, whether it does or not doesn’t matter. It’s not that the engine itself can’t deal with burning alcohol-poisoned gas (although older ones like my ancient snowblower that’s almost as old as I am don’t like it). It’s that the gas tends to sit in the tank for a long time (especially with snowblowers in mild winters), and some sits in the carb for just as long, and if you don’t put a fuel stabilizer in it it will go bad and gum up the works. A lot of people have to do what should be unnecessary carb services on small engines because the stale gas fouls it.

Actually the opposite is true. Tire pressures on the placard lean higher because it helps the fuel economy numbers.

For decades Corvettes were labled 35 psi. The Corvette engineering folks let it be known the tuned the car for 30 psi to improve the ride.

I agree with the need for more spark advance but that isn’t possible on most smaller engines.

More octane, more spark advance, more Powahh!

@VDCdriver. Thank you for the recommendation. I will probably.get a battery leaf blower in the near future.
One problem that I have is replacing something like an AC powered leaf blower that still works with a battery powered leaf blower. I had the same problem replacing our cathode ray tube television with a flat screen TV when the old television still worked. I know a mower powered by a lithium ion battery would be much more convenient than my gasoline powered mower, but what I have still works.
The same is true with vehicles. When the one I have still functions, I don’t want to replace it just to get new features.
My real problem is that I don’t like to spend money.

I have a set of tires that have been run at +4 psi above spec for 50,000 miles.
The wear is exactly even.

That may be true, but car debelopment engineers set the pressures as high as the tire vendors let them and as low as their mpg gurus let them. You don’t have to answer to either.

Only to the Holy Owners Manual

I’ve run my tires at 4 to 5 PSI over most of my life with no problems.

In my youthful high school days I knew a couple of similar aged guys who like me had to watch their money. Gas was 30 cents a gallon back then but…
They decided to hit a few oil leases and heisted a barrel of drip gas to fill their cars with. They regretted it when the fuel in the carburetors and gas lines ran out and the drip started to hit. The engines would barely even run, knocked, and belched out clouds of smoke. In the early 1900s one could have gotten away with that more than likely.
The octane rating of drip gas is between 30 and 50. Ouch.

Probably something closer to worship. :wink:

Some of us aren’t averse to asking for and checking directions. :wink::grin:

True. Many years ago when our daughter was about 3 months old my wife and I were heading to a holiday party at my wife’s then boss’ house. We missed a turn and I was the one who decided to stop for directions. The Mrs. wanted to keep driving. The point being, not every answer is to be found in the holy Owner’s Manual as in your case. “86 octane or higher” isn’t a sufficient answer.

Of course the answer isn’t necessarily there. Many, if not most, manuals are short on details and/or poorly written. No harm in giving it at least a quick look through when getting a new machine even if the info is full of pertinent holes. Guess that makes them “holey.” :wink::grin:

The thing to remember is that owner’s manuals are just one point in time. Things can change and they’ll never send out updates for a ten year old manual. Sometimes the manufacturer’s sites will provide the updates there or in their Q&A if they have one. That’s what Briggs did with oil anyway. Even in car factory manuals there can be out of date information that only the factory mechanics know about.

Edit: I just got gas a little while ago and noted again the premium pump had the non-oxy label on it. The label said for boats, antique cars, small engines, ATVs, off road vehicles, etc. Who am I to argue with a label? I don’t know what the octane rating is but I’ll just continue doing what has worked for me over the past ten years. Your results may vary as the finance guys say.

I use 90 octane in all my small engines.Not because of the octane but because it is the only non-ethanol gas around where I live.

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I’ve shared this before but some years ago I owned a 2000 Chevrolet Cavalier. An amber light shaped like a wrench came on on the dash one evening when I started the car. I turned off the ignition, opened the hood and looked for anything obvious, then checked the Owner’s Manual. It said something to the effect of, “This light means there’s something wrong with your vehicle.” Wow, that was helpful. It turned out the light was an indicator of non-emissions-related problems and in my specific case I had a headlight out and it probably failed some test when the daytime running lights came on. Naturally when I turned the ignition off I turned the daytime running lights off too so I didn’t see the burned out headlight.

So I have an old Briggs mower (15 y) which has been run on 10% ethanol regular.
It just had a carb replacement.
Should I move to ethanol free premium, or stay with what I had?
To anticipate troll #32, no there is no ethanol free regular here.

If you run with a non-ethanol gas with a fuel stabilizer, you don’t have to worry about draining the fuel systems each time the engine is stored away for the season.