Chainsaw Fuel and Storage Opinions 2023 (sticky?)

[iowa_jim]

Hello all, I've heard a lot of conflicting information regarding what fuel to use for chainsaws, particularly when stored. I was watching a YouTube expert who was explaining how ethanol is from corn and that ethanol degrades into corn syrup in the tank and gums things up. I was enjoying it until I realized he was being serious. So let's cut through the nonsense and see if we can achieve anything close to a consensus on this.

Octane - ignoring the ethanol aspect briefly, is higher octane fuel any benefit? 87 vs 91 vs 93?
Ethanol - modern saws are built for E10, so...
Does this mean that ethanol is no longer a problem, or
Does storage of ethanol fuel in the saw still present a problem?
Ethanol with stabilizer - does this remedy the concerns entirely?
Canned fuel -
shelf life?
allows extended periods of time with gas left in the tank?
Chainsaw storage - how long can we leave fuel in the tank before we create a problem when starting the saw again? 1 day? 1 week? 1 month? 3 months? 1 year?

These are the aspects of the question I can think of, but what other aspects are there? Reformulated gas for summertime use cause any issues?

Cheers, Jim (in Iowa)

 

[farmer steve]

I'll go first Jim. When I bought my first saw I ran E87 octane with the stihl oil. Bought my 2nd and 3rd saw and continued this practice. Saws may have sat for months with some mix in them. I never had any issues. My saws always get cleaned off at the end of the day. Fast forward to present. All my saws get non E91 octane fuel. Stihl using stihl oil at 45:1. I usually park them with an empty tank. I cut anywhere from 30-50 cord per year. You will get a slew of answers. Sift through them. Good luck. FS.

 

[OM617YOTA]

Octane - ignoring the ethanol aspect briefly, is higher octane fuel any benefit? 87 vs 91 vs 93?

Manual recommends 91, go with that.

Ethanol - modern saws are built for E10, so...
Does this mean that ethanol is no longer a problem, or

Not a problem to run the saw on. Tune for what you're running.

Does storage of ethanol fuel in the saw still present a problem?

Still a problem to store on. Area dependent, some folks claim to get away with stuff that would kill a carb here.

Ethanol with stabilizer - does this remedy the concerns entirely?

Not a remedy for ethanol fuel at all.

Canned fuel -
shelf life?

A long time, multiple years in the can.

allows extended periods of time with gas left in the tank?

Yep.

Chainsaw storage - how long can we leave fuel in the tank before we create a problem when starting the saw again? 1 day? 1 week? 1 month? 3 months? 1 year?

Ethanol fuel, a month maybe.
Non ethanol fuel, several months.
Canned premix, a year +.
Area dependent, some folks claim they have no issues letting ethanol fuel sit for a year in their equipment. My area, equipment stored with non ethanol fuel in the carb won't start in a year.

Tune for what you're running, regardless of what that is.

My personal recipe is non ethanol premium, a double dose of Stabil, stored in air tight NATO surplus cans, rotate yearly. Canned premix in the two stroke stuff, drain the carb for storage on the four stroke stuff.

Edited to change my own text to a different color.

 

[HansFranz]

I try to use non-ethanol fuel at 40:1 and if I don't think I'll run the saw again for more than a month, I'll dump out any remaining fuel (into the lawnmower) and keep starting the saw until it runs out of fuel. YMMV.

 

[Sidecarflip]

Canned fuel here (Echo Red Armor or Tru-Fuel 50-1) or 40-1 with a new saw, first couple tanks... Don't use them constantly so if they are gonna sit, I'll run them dry until they stop and the choke them to get the last of it out. If they sit for an extended period, a shot of Stabil fogging oil in the carb and a pull over. Same deal with the brush trimmer. Conventional bar oil, I use Menards and buy it when on sale. All my bars have greaseable noses so they get a shot of high quality bearing grease regularly.

Interestingly, my 42 year old Stihl 028 I bought new and ran on unleaded weasel pee for years got tempermental on pump gas and Stihl pre mix oil and when I switched to canned fuel it lost it's tempermental attitude.

I keep my 075 and 090 dry all the time as they just sit and collect dust. The cylinders are fogged with Stabil fogging oil of course.

Never replaced a fuel line from it getting hard from running e-gas either.

028 has original fuel line at 42 years old. Bought the 75 and 90 at the same time as the 028.

All my saws are muffler modded including the new Echo's and the Timber Wolf has a Stokel stack and foam air cleaner on it too.

 

[Sidecarflip]

Do keep in mind that the gummit has approved E15 to be sold as motor fuel and far as I know of, E15 is death on a small air cooled engine so check the pump for corn alcohol content before pumping if you don't use canned fuel like I do.

 

[berrnard]

https://www.pure-gas.org/here ya go, check whats near you
i put star tron in when i refill my jug for mix gas and non ethonol fuel. i do nothing else special for winter storage and saws start right up in spring.
my recent jug before i refilled, ive had for about a year and no issues
call for 50:1 on newer saws, but i always error on the side of caution and mix rich. about 40ish:1

 

[Sidecarflip]

Nothing near me..... Not that I'd buy it anyway. here in Michigan it's called Recreational Gas and it sells per gallon way above premium. For as much as I use, I'll stick with canned gas. I might use 3 gallons a year total.

 

[Seachaser]

Ask any auto mechanic or you can take ethanol and put in glass container. Let sit for a while. That’s all the proof I need.

 

[muddy42]

Octane - I havn't found any difference in the range 91-97
Ethanol - horrible stuff, avoid like the plague, dissolves adhesive/seals/plastic. Attracts water.
Ethanol with stabilizer - does this remedy the concerns entirely? - No. check out youtube for ways to remove ethanol, never done this yet.
Canned fuel - A good idea for occasional users. Yes its expensive, but it only needs to save one expensive repair or replacement machine to pay for itself
shelf life? - canned fuel will last for 5 years if unopened, 2 if opened. Pump fuel will last for 3 months for a four stroke, but 1 month if mixed with oil for a two stroke.

what do I do?
I use only canned ready mixed fuel for my (older) chainsaws. In the summer I do so much brush-cutting that I use pump fuel, but I flush it out with canned fuel at the of the grass season. My brushcutter is a modern machine that hopefully can cope with small amounts of ethanol.

 

[berrnard]

Pump fuel will last for 3 months for a four stroke, but 1 month if mixed with oil for a two stroke.

1 month for mixed?
where is that info from?

 

[muddy42]

1 month for mixed?
where is that info from?

Yes that's correct, I'll aim to use mixed two stroke fuel within a month of getting it from the pump and mixing it. It may last longer but I don't want to find out!! Watch out, some under-used pumps can be selling very old fuel. The ratio (e.g. 50:1) is irrelevant for its lifespan, its the fuel itself than degrades and you get odd varnishing effects and separation. It smells bad too. I'm no expert but I find two strokes are more sensitive to bad fuel than four strokes.

I also live in the UK where our fuel is poor and full of ethanol.

 

[Sidecarflip]

Lets see, E-gas destroys fuel lines, gums up carbs (especially on 4 stroke engines) that sit for long periods of time without fuel stabilizer in it. Don't know how many times I've had to pull a carb (4 stroke) take it apart and give it a bath in my ultrasonic cleaner to get the crap out of it.

I use Marine Stabil in all my infrequent use 4 strokes and canned fuel in the saws.

Do keep in mind that the Federal EPA is allowing up to 15% corn alcohol in pump gas now and most 4 stroke air cooled engines don't do well (lawnmowers and such) on 15% E-gas, so check the pump for percentage before pumping into your gas can.

 

[Sidecarflip]

Ask any auto mechanic or you can take ethanol and put in glass container. Let sit for a while. That’s all the proof I need.

Which is exactly what it does in your engines fuel tank or carb bowl. Called 'Phase Separation' for you tech heads. When static for a period of time which can vary depending on temperature and how fresh the fuel is, the gasoline rises to the top and the corn alcohol sits on the bottom and alcohol is hydroscopic, that is, it attracts water just like conventional brake fluid does so any condensation in a fuel tank mixes with the corn alcohol and creates a goo the destroys fuel lines, gums up conventional carbs, destroys the diaphragms in chainsaw carbs and cause issues.

Why I only run canned fuel in my saws because they may sit for a protracted amount of time, unused. No issue with canned fuel as it contains no corn alcohol.

Always keep in mind that E-gas cannot be transmitted via pipeline because it's inherently corrosive and the corn alcohol is added to the gasoline at the fuel rack before it's trucked to the filling station.

if you use your saws frequently, E-gas and an oil mix isn't a issue. I don't.

 

[huskihl]

Yes that's correct, I'll aim to use mixed two stroke fuel within a month of getting it from the pump and mixing it. It may last longer but I don't want to find out!! Watch out, some under-used pumps can be selling very old fuel. The ratio (e.g. 50:1) is irrelevant for its lifespan, its the fuel itself than degrades and you get odd varnishing effects and separation. It smells bad too. I'm no expert but I find two strokes are more sensitive to bad fuel than four strokes.

I also live in the UK where our fuel is poor and full of ethanol.

I believe you have the right intentions, but you misunderstood what you read about regular fuel versus fuel with two-stroke oil in it. In my experience, two-stroke oil helps fuel to last longer. Most are trying to use fuel up quicker for the smaller two-stroke motors because as you mentioned, two strokes do seem to be fussier than larger four stroke engines.
The reason for using the fuel up is because of two strokes being fussy, not because it has two-stroke oil added to it

 

[bwalker]

I believe you have the right intentions, but you misunderstood what you read about regular fuel versus fuel with two-stroke oil in it. In my experience, two-stroke oil helps fuel to last longer. Most are trying to use fuel up quicker for the smaller two-stroke motors because as you mentioned, two strokes do seem to be fussier than larger four stroke engines.
The reason for using the fuel up is because of two strokes being fussy, not because it has two-stroke oil added to it

I could see two cycle oil increasing storage time before the fuel goes bad if the oil your using has stabilizer in it. The effect is minimal and even a double dose of something like Stabil won't protect gasoline for years. Canned fuel and avgas absolutely will store for years. Seafoam or MMO don't do anything as far as I can tell from a storage or any other standpoint. They do work well for making your wallet lighter.
It's also a good idea to dump the tank before using even if it's fueled with avgas or canned fuel. Octane decreases with the loss of light ends and starting becomes more difficult with stale fuel. It also makes your carb tuning leaner by default.
Modern saws do use rubber and plastic parts that are more resistant to ethanol. However the metal parts are not more resistant and corrosion is still very much an issue. I'd avoid ethanol fuel if at all possible.

 

[OM617YOTA]

Octane decreases with the loss of light ends and starting becomes more difficult with stale fuel.

When I rotated through my 2 year old non-ethanol premium, stored in an air tight metal can with a double dose of Stabil, the only difference I noticed from normal was that my car pinged a couple times on hard acceleration, once. Computer sensed it, adjusted timing, and I never heard it again, but normally I don't hear any pinging at all. Car ran perfect otherwise, that one instance of pinging was the only indication I had that I was running 2 year old fuel.

The same fuel gave zero indication of anything different in my truck, pressure washer, and generator. The car has the highest compression ratio of the group.

Next time, I'll only store one year.

 

[Sidecarflip]

Seafoam or MMO don't do anything as far as I can tell from a storage or any other standpoint. They do work well for making your wallet lighter.

You got that right but it seems to have it's legions of followers and I'm not one. Seafoam is good for removing carbon from GDI engines, I use it every oil change but my only use and MMO makes good air tool lubricant.

 

[bwalker]

You got that right but it seems to have it's legions of followers and I'm not one. Seafoam is good for removing carbon from GDI engines, I use it every oil change but my only use and MMO makes good air tool lubricant.

Funny you mentioned GDI. I had a GMC Acadia that had carboned up intake valves. Tried the Seafoam GDI cleaner and it didn't do anything. CRC GDI cleaner did work, but it took three cans and the results were not great by any means.
When added to fuel I've never seen seafoam do a damn thing and base that on actually viewing the cylinders with a borescope.

 

[bwalker]

When I rotated through my 2 year old non-ethanol premium, stored in an air tight metal can with a double dose of Stabil, the only difference I noticed from normal was that my car pinged a couple times on hard acceleration, once. Computer sensed it, adjusted timing, and I never heard it again, but normally I don't hear any pinging at all. Car ran perfect otherwise, that one instance of pinging was the only indication I had that I was running 2 year old fuel.

The same fuel gave zero indication of anything different in my truck, pressure washer, and generator. The car has the highest compression ratio of the group.

Next time, I'll only store one year.

If the fuel was sealed in metal containers with no or little head room it definitely helps with storage.