McCulloch Mini Mac 35 fuel type

The instruction manual says "use regular grade gasoline" in my McCulloch Mini Mac 35 chainsaw. Does this mean REGULAR leaded gas? As in the kind that can't be purchased anymore? Or does this just mean regular gas as in the kind sold at a gas station?

the regular gas at station

When the manual was written, regular was probably leaded gasoline. Times change, probably for the better in this case, at least as far as our lungs are concerned.

Fortunately, the lead really served no purpose in 2-stroke engines, so the current "regular" unleaded gasoline is perfectly fine.

Some will argue that the ethanol will ruin your fuel system and that you need to find ethanol-free gasoline, or use that expensive $7/quart premix from the chainsaw store.

On an old chainsaw like your Minimac 35, that probably hasn't been run in decades, I am confident in saying that the fuel system is *ALREADY* a bunch of melted rubber mush, and it hasn't seen a drop of ethanol.

Explain that, you anti-ethanol types...

In MN it's best to use the premium without ethanol for mixed fuel, that's what I do and I have no problems. Sometime I am using fuel that is over a year old.

Thank you to everyone who responded. You were all big helps...

"Fortunately, the lead really served no purpose in
2-stroke engines."

Untrue, 2 stroke engines will detonate due to fuel
with too low octane same as 4 stroke.

I use 87 octane loading up with that nasty ethanol and have never had a problem.

Lead was added to gasoline to increase octane and lubricate valves, A Mini Mac 35 doesn't have any valves. To use unleaded gasoline the newer engines have harder valve seats. The problem with Ethanol is two fold, 1- older stuff used rubber that isn't ethanol proof so ethanol enhanced fuel tends to dissolve some of the older rubbers and plastics. 2- Ethanol absorbs water, water tends to cause problems in fuel systems if it's left to lie around in it.

Friend that is an A&P (Airframe & Powerplant A.K.A Airplane mechanic) tells me must of the STC (Standard Type Certificate) modifications to run autogas in an Airplane is to replace the plastic and rubber to ethanol proof stuff and change out other parts that get corroded by the higher moisture in autogas.

So if you must or want to use regular gasoline with Ethanol don't let it set in the unit after you're done using it.

I work on a lot of older saws. If the Mini is still in running condition and is currently starting and running with no issues, then I'd make the effort to use ethanol free fuels. True, fuel lines will degrade over time just sitting there, but ethanol DOES severely affect some types of fuel lines, fuel tank caps, and in some cases the case of the saw itself by discoloration. Newer saws usually have upgraded plastics that can handle ethanol.

If the Mini isn't running and the fuel lines need replacement, brush up on all your cuss words because you'll be running through them all before the job is done. Not fun to work on at all.

No explanation required or given. There are reasons to be FOR or AGAINST ethanol. My main objection to ethanol is the lack of CHOICE. It has been forced upon us prematurely.

FACT: ethanol contains LESS BTUs per unit than gasoline.

FACT: ethanol DOES attack some plastic and rubber compounds.

FACT: ethanol absorbs moisture from the air. This causes phase separation which leads to a short shelf life .

The damage is real. Your statement that you never had a problem does NOT invalidate all other claims of damage. I have seen many engines on outdoor equipment have varying amounts of ethanol damage - from no damage to extensive damage. For some reason, some equipment tolerates the ethanol better than others.

Given a free choice, the ethanol would disappear as it has in the past when marketed as an "alternative" fuel. I do remember the "gasohol" of the 1970s. And again in the '80s. This time it is force fed to us. I still like to have a choice in the matter.

Oh....back to the chainsaw....
MOST fuel available when that saw was built was unleaded. The last of the leaded fuels available for on-road use were pretty much gone before 1980. Is the saw older than 35 years????