2 Cycle Fuel Question.......

[cptjack]

at 8.00 a qt ,I use high test only gas around here that has no ethanol

[rototerrier]

1) More oil than is necessary simply blows out the pipe and/or fouls the plug
2) A higher oil ratio = a lower fuel ratio = running leaner.

Most small engines now come preset and expect the fuel/oil ratio to match those preset settings. If you deviate from the recommendations by adding more oil, then you will be running the engine leaner based on its preset tune. If you add less oil, then you will be running richer. It's not an issue if you can tune the engine. But if you plan on just running it as you received it and not turning it, then it's probably best to stick with the recommended mixture since that's what it's most likely setup for.

I always run Ethanol free fuel mixed with RedLine 2T at 40:1 from my chainsaws and blowers to my $500 heavily modified RC helicopter and plane Engines. But I also tune my engines so they all run perfectly on it.

Personally, I've never seen a situation that called for more than a 40:1 ratio.

Many many years ago, before I got into high dollar RC engines, I ran everything at 50:1 and even used Amsoil 100:1 at, you guessed it, 100:1. No issues, ever.

Per the engine modifier's request and instruction, I switched to using 40:1 RedLine and just made that change across the board. Figured what was good for my $500+ engines was more than good enough for my cheap weed wacker, blower, and chain saw engines.

[DerekP Houston]

We use this now and our tools run like a raped ape.
http://trufuel50.com/product-info/

Yeah, i use so little fuel for my weedeater and leafblower i switched to Trufuel as well. no more clogged lines or ethanol issues, just one pull and they fire right up. Ridiculously over priced for what it is though.

[44man]

I had nothing but troubles with oil, carbon and plugged exhaust. I used Stihl synthetic at 50 to 1 along with all other brands. Oil would drip from mufflers all over the garage floor. I was always fixing.
I found Opti II and all problems went away. It comes in a little pack for a gallon of gas. 50 to 1.
Every octane gas here has alcohol in it. Have to go to a Liberty station to get rid of it, place is too far and it is expensive.
Sea Foam seems to take care of it.

[rond]

I run premium in all my air cooled engines, as per the owners manual.

[dragon813gt]

If you can't buy ethanol free gas you can make it from ethanol laden gas. All you do is add water, agitate and let it settle out. The water picks up the ethanol and then you drain it out. You wan to use distilled water but this process works. I did it before a station locally started selling ethanol free gas.

[funnyjim014]

I run eth free 91 with the factory oil that you dump into 1gal of fuel. My farm boss can tell the difference with the eth free fuel

[sac]

Like Rototerrier said you will have to tune for the new mix, I tune my saws every time I use them depending on the day.

[prestonj12]

If I'm not using a lot I buy the ethanol free premix at Lowes. The stuff they sell by the quart for around $6. That stuff has no additives, detergents etc. 92 octane. I run a tank of this stuff about every third tank. It's sorta like a tuneup in a can. All my 2 cycle toys get this treatment. Keeps em from carb rebuilds so far.


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[David2011]

I can't imagine that the octane rating would matter on a 2 stoke chainsaw engine. So for the 87 vs 89 octane question, I would buy the 87 and carry on. However, if it is at all possible to purchase non-ethanol fuel in your area, I would highly recommend non-ethanol fuel in ALL of your small engine applications.

You are correct. Octane really doesn't matter in unmodified small engines. The cylinder volume is just too small for octane to be an issue. If you don't mind paying the price and they'll sell it to you, get some 100 Low Lead gasoline at a general aviation airport. Don't get excited about 100 Octane; that's just a re-ignition retardant and it won't burn an engine up. If you burn enough, the lead will build up on the spark plug. Aviation gasoline is much cleaner than automotive pump gas and has no alcohol added. It will not gum or varnish up in storage. I'm changing to 100LL for my bigger radio controlled airplanes because it doesn't gum and varnish if I don't get to fly for a while. Even if you don't want to pay for av gas all season, at least run it as the last tank or two before the storage season and the carb won't be sticky or varnished up next time you need the tool.

[too many things]

check at your sunoco station many Carey the al free called rec gas

[snowwolfe]

I been using 50 to 1 for decades on all my 2 strokes and never had any failures.

[dkf]

I usually use Amsoil Sabre 100:1 oil in aircooled (weedeaters, chainsaws, etc) at around 60:1 with 87 octane pure gas. My watercooled two stroke outboards get Amsoil Sabre outboard for the premix ones at 70:1 and Amsoil HP Injecter in the oil injected ones again with 87 octane pure gas. You can run richer, it burns very clean. If you don't have the higher compression that requires higher octane fuel then it does nothing to help. All my 2 stroke outboards don't even have a 7:1 compression ratio, higher octane is a waste for them.

In the R/C gas boat world on 30cc and smaller engines (some making well over 6hp) they run coleman fuel with 8-10oz of oil per gallon.

If you can't buy ethanol free gas you can make it from ethanol laden gas. All you do is add water, agitate and let it settle out. The water picks up the ethanol and then you drain it out. You wan to use distilled water but this process works. I did it before a station locally started selling ethanol free gas.

If you do that you have to start with higher octane fuel. (like 93) When you pull the ethanol out of the fuel the octane will drop.

[dragon813gt]

I'm aware. I wasn't going to write out all the details when they're readily available online. I was simply pointing out another option.

[HangFireW8]

The oil ratio depends primarily on the quality of oil used, and after that the tuning of the engine. 87 is usually fine unless you have a compression engine mod. Keep in mind more oil brings down the octane, less oil retains octane.

-HF

[Rick459]

the little bottles of 2 stroke oil are approx. 2.6 oz. mix 1 bottle to every gallon of gas used. you will be fine.

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[texasnative46]

To All,

I just wish that I could FIND some alcohol-free gas nearby. = I've found none nearer to me than 2 hours round-trip away by car.
(As I have about a dozen pre-1965 Johnnyrude OB motors, I need a lot of it, too.)

yours, tex

[km101]

Thanks for all the info. I have learned A LOT about small engines and fuel.
Like texasnative46 I wish I could find non-ethanol fuel or some place that would sell me Ava-gas. I can't find a source here north of the DFW metromess. But I have learned enough here to solve my problem!

THANKS to all of you!

[dragon813gt]

Lone Star Mobil in Allen, TX is the closest one I could find north of Dallas. But it's not exactly close by.

[Petrol & Powder]

2 stoke engines typically don't have an oil sump or pressurized lubrication system. The only lubricant available in the crankcase is the oil/gas mixture. That oil/gas mixture has a lot of demand placed on it; it must lubricate the big end of the connecting rod, the wrist pin, the rings, the piston skirt and the two outer crankshaft bearings. The good news is because it's constantly being replenished; that gas/oil mix only has to work for a brief period of time. More oil improves the lubrication but it comes at the cost of less efficient combustion and less power. Like most things in life - it's a compromise.
If the bearings can stand a thinner oil mix then there's an advantage to running more gas and less oil. It comes down to what the engine can tolerate. A little more oil doesn't hurt much but it comes at the cost of smoke, plugs that foul easier and slightly reduced power.

As for alcohol and gasoline - The ethanol causes more problems in small engines than it's worth. It also causes huge problems with storage of fuel. Fuel stabilizer certainly helps but pure gas is even better.

Octane rating: this is probably one of the biggest scams around and it's easy to sell because people want to believe it's true.
High compression engines need high octane gas to run without detonation [knocking or pinging]. Increasing the compression ratio (to a point) is one of the ways to increase power but high compression requires high octane fuel to take advantage of that higher compression ratio.
Using high octane fuel in an engine that doesn't need it to operate; DOES NOT PRODUCE ADDITIONAL POWER. Putting high octane fuel in a low compression engine doesn't magically make it run better, stronger or more efficiently. In fact, it may even be less efficient.
When people buy high octane fuel and tell themselves that they are getting: more power, better gas mileage or some other perceived benefit - they are just engaging in a self fulfilling prophecy. They want to believe they are getting better performance so they do believe they are getting better performance. The fuel companies are happy to sell you more expensive gasoline and they are not going to educate you.
Now, there are some high compression engines that have the ability to produce maximum power on high octane fuel and compensate for lower octane fuel when necessary. Those engines have knock sensors and computer controlled ignition and fuel systems that reduce power output when they are fed lower octane fuel. However, a low compression engine that runs fine with 87 octane fuel will not magically produce more power if you supply it with 93 octane fuel.