Fuel Additive for Chain Saws

[Jim Laumann]

I wonder if "lousy" gas is a regional issue? I've been treating all of my gas can fuel w/ red stabil for years - both 2 and 4 stroke. I can't say that I've had issues - some of my engines sit for months at a time. My 4 strokes get plain unleaded, the two strokes I've been trying to feed premium, or better yet, unleaded premium (something my local small engine service center recommended).

Jim

[phil harold]

most small engines do run better on non ethanol gas

cant you just buy non ethanol gas at the pump?

here it is 2 octane points lower and about 10¢ more per gallon

my major cure for most of my small engines is to soak the carb in seafoam and then blow all the holes clear with compressed air

[Stephen Cherry]

I just had to buy a new blower and weedwacker as my other were in OK shape but clogged up and the price of new carbs is not that cheap to justify on older machines.

My plan is to use the machines with pump gas, pour out the unused gas, run the machines out, then add a little of the store bought non-ethanol premix and store with that.

What a scam and a half. I've read that the energy needed to produce the corn is a good portion of the energy that you get from the ethanol, but at least the farmers got what they wanted.

[Sean Kinn]

The advice I got from a long term dealer in my area was as follows:
1. Use the premium gas at the pump, as it often has more stabilizers in it from the start since it typically sells much slower than the 87 octane cheap stuff.
2. For Stihl tools, use the premium synthetic mix they sell. Stihl even doubles the warranty on their new machines if you purchase a six-pack of the mix at the time of purchase....that says somethign right there.
3. Only mix up a gallon (or even a half gallon) of fuel at a time.
4. Discard mixed fuel/oil or plain gas after three months. There is no reason to use old gas in your power tools. Therefore, additive is not necessary. I personally dump straight gas in my wifes car. Any left over oil/gas goes into my old Cub Cadet riding mower at no stronger than a 1 to 4 ratio of mix/gas to gas.
5. Drain machine if it will sit longer than one month, or sooner if it will not be used heavily and with fresh gas after the month

[Steve Baumgartner]

The advice I got from a long term dealer in my area was as follows:
1. Use the premium gas at the pump, as it often has more stabilizers in it from the start since it typically sells much slower than the 87 octane cheap stuff.
2. For Stihl tools, use the premium synthetic mix they sell. Stihl even doubles the warranty on their new machines if you purchase a six-pack of the mix at the time of purchase....that says somethign right there.
3. Only mix up a gallon (or even a half gallon) of fuel at a time.
4. Discard mixed fuel/oil or plain gas after three months. There is no reason to use old gas in your power tools. Therefore, additive is not necessary. I personally dump straight gas in my wifes car. Any left over oil/gas goes into my old Cub Cadet riding mower at no stronger than a 1 to 4 ratio of mix/gas to gas.
5. Drain machine if it will sit longer than one month, or sooner if it will not be used heavily and with fresh gas after the month

+1 on what Sean says. Both MA where I live and ME where I summer require 10% ethanol - no way to get gas without it. It has been destroying 2-stroke outboard motors and chainsaws around here ever since! There are a number of problems. Unless the rubber parts in the fuel system were made with ethanol resistant plastics, it softens them and the goo ends up in the carb, clogging it. It will dissolve resin out of fiberglass (used in many older built-in boat gas tanks), **really** clogging carbs and filters. It absorbs water, which causes the gas to go sour sooner. So, all the mechanics around here say:
1. Always use one of the enzyme additives (not the old stabilizers, which aren't adequate for ethanol)
2. Always run the motor dry if you won't be using it again within a week
3. Check and replace any rubber/plastic hoses, seals, etc that appear to be deteriorating
4. Don't buy more gas than you will burn up in a month

[ian maybury]

My experience with alcohol (actually methanol) has been mostly in running racing motorcycles. As best I can remember (don't treat this as fact) it's 'different' in a few ways (presuming that ethanol and methanol have fairly similar characteristics), many of which have been touched on already:

1. The air/fuel ratio giving optimum combustion is richer (needs more fuel) than for petrol. On bikes running 100% methanol carburettor jet sizes need to be quite a lot larger. (to flow about 150% as much fuel) MPG is significantly lower. The effect isn't quite so marked with ethanol, but the effect of adding it for engines set up for petrol is likely to be to very significantly 'lean' out the mixture.

2. It delivers best combustion at higher compression ratios than does petrol.

3. It's quite a bit harder to vapourise at low temperatures, and consequently is likely to make cold starting more difficult - and make carburettors more prone to freezing in cool and humid conditions unless heaters are used.

4. It attacks many varieties of paint, rubber and plastics not damaged by petrol that were commonly used in older vehicles.

5. It absorbs water from the air, and becomes harder to vapourise as a result.

6. It's not compatible with all types of oil, especially when mixed with the fuel as in two stroke engines.

It's actually got a lot of positive characteristics - it tolerates very high compression ratios without knocking/detonation, it burns cleanly, it runs cooler, it's combustion efficiency is much less influenced by variation of the air/fuel mixture away from the optimum than petrol, and it probably produces less by way of acids etc to contaminate lubricating oils - and most engines deliver better power and torque on it at lower rpms than on petrol.

My sense is that issues arise mostly out of two factors: (1) because an engine is not optimised for the specific fuel in question - or for alcohols at all, and (2) because a given engine may encounter differing petrol/alcohol blends in use.

There's an obvious risk of damage caused by the solvent effect of the alcohol in engines not originally designed to use it, and air/fuel settings cannot be optimum if varied alcohol and petrol mixtures are used.

Water absorbtion by fuel in tanks is another issue - basically because it changes the combustion characteristics of the fuel, and causes starting problems.

ian

[Anthony Whitesell]

Blowing out the carb and running it dry is the greatest cure for preventing untreated fuel from varnishing or gelling in the bowl and carb. I have always treated the fuel and topped off tank (with the aforementioned exception of my chainsaw). The less air left in the tank leaves less room for condensation to form and thus less chance of water in the fuel.

I'm going to have to go out on a limb and guess that my tools are too old to care about ethanol in the fuel; '74 Simplicity tractor, '65 Gravely tractor, '82 McCulloch chainsaw, '80 Troy built tiller, '98 weed trimmer, and '99 Craftsman lawn mower.

[Dave Lehnert]

The $4.99 can of premixed fuel at O'Reily is 12oz by the way. Also, the stuff in the Sears link is 40:1 while the O'Reily stuff is 50:1 which is what Stihl and Echo use IIRC.

Dave, I never had to take my Homelite blower to the shop--it only lasted 20 minutes before the blower wheel shed it's vanes so I returned it and bought the Echo. I've shied away since. Though I did buy an electric pole saw that seems decent.

That 12oz on the O'Reily site is wrong, It is 32 oz. I looked at it in store.
Can't find it on Sears site but they do stock 50 to 1 mix in the stores.

I'v used the Stihl 6 pack oil since day one. Mix with gas, Use the saw, dump all gas and run dry. Still in the shop twice before I use my 4th bottle of oil.

[Ron Jones near Indy]

Stihl does recommend that you use the mid-grade of gasoline. Supposedly makes the engine run cooler.

[Gary Kman]

First let me say that I have less brand loyalty than a dog has for fire hydrants. I have a small Stihl commercial saw, a 80cc Echo felling saw and a cheap Echo weed eater. They are all about 8 year old. The saws will run a few tanks of gas maybe 4 times a year and the weed eater every couple of weeks all summer. I use Stihl oil and whatever regular gas (containing ethanol I'm sure) they are selling. I keep it until I use it up and mix a fresh batch. None have had fuel problems. All start easily. Stihl claims there is stabilizer in the oil so that's all I use. Eight years, no special treatment, no problems. If ethanol is such a culprit, you would think it would have nailed me by now, wouldn't you?

On the other hand. Four strokes, ran hard, left with gas in the carburetor. Residual engine heat plus only a couple weeks time ruins the gas in the carb and it absolutely will not fire. Drain the carb and refill with the same gas (but from the fuel tank) and it fires right off. Five kw generator I always run dry, 4 wheeler, 900 Kawasaki, mowers get red Stabil over winter. Even running dry can fail. Got to use a log splitter if I could get it running. Finally did - spider nest in the main jet.

[Matt Meiser]

That 12oz on the O'Reily site is wrong, It is 32 oz. I looked at it in store.

Yep. I actually went ahead and bought a can last night while there buying LOML a new battery for her car (guess I've got her birthday gift is taken care of .) Since I probably only go through 1-1/2 gallons a season, probably 1/2 - 2/3 of that doing spring cleanup it probably makes sense so I'm going to give it a try. And without the Ethanol, in a sealed container, it probably has a long shelf life until opened. Now I don't have to keep mixed gas on hand all winter just in case I need to use the chain saw after an ice storm.

[Anthony Whitesell]

Why would the shelf life of gasoline in a sealed container change based on buying in a can from the BORG or buying it from the pump?

Out of more curiosity, I wonder how they are getting around the 10% ethanol mandate?

[Matt Meiser]

Not sure as it specifically says it doesn't contain ethanol. Based on discussion above I'd think that right there would give it a longer shelf life. Plus it has the oil and stabilizers in it. And I'd think like canned food, it would be vacuum sealed, but maybe that's a bad assumption.

[Anthony Whitesell]

For those that believe the ethanol is a problem, then this stuff would circumvent it...for now. The biggest thing that I noticed about it (I've seen it on the shelf for about a year now) is that it is in a metal can, not plastic.

As I keep pump fuel for months on end unmixed and untreated in a metal gas can, mixed and treated in plastic cans, or unmixed and treated in the tank for storage of the equipment.

[Dave Lehnert]

Yep. I actually went ahead and bought a can last night while there buying LOML a new battery for her car (guess I've got her birthday gift is taken care of .) Since I probably only go through 1-1/2 gallons a season, probably 1/2 - 2/3 of that doing spring cleanup it probably makes sense so I'm going to give it a try. And without the Ethanol, in a sealed container, it probably has a long shelf life until opened. Now I don't have to keep mixed gas on hand all winter just in case I need to use the chain saw after an ice storm.

Matt, Had a chance to fire up my Stihl today using the O'Reily mix. After a minute or so I did notice it was running much stronger on the stuff. Ran like a champ.
At first I said no way would I use that liquid gold but like you, My saw use is very limited to yard cleanup so it is not bad. I trimmed a few trees today and used less than 1/2 a can.