Ideal Chainsaw Fuel

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MooneyPilot

MooneyPilot

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Just thought I’d post this information. You might not be aware that 100 LL is available in almost all areas of the US At the local airport. It makes fabulous fuel for chainsaws, especially those that have been modified with advanced timing. It is also alcohol free.

Most all airports have self service pumps that can be used with a credit card. The system may ask for a tail number, but just make one up. Some airports have very tight security, but most do not. Most local General Aviation airports are easily entered and the self service pump is easily accessible. In our area the current price is $3.59 per gallon, but in some airports especially near meteopolitan areas it can go $6.00 and even higher. My theory is that i don’t burn tons of it and it keeps my saws healthy. It is legal to buy it for non aviation use as long as it is not used in a catalytic converters equipped vehicle.

Anyway I just wanted to share this with those of you who might be interested. I use the 100LL with Stihl Ultra and it works great.
 
Huskybill

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I think they ran aviation fuel which was over 100 octane with 100:1 optimol 2 stroke.

Some guys at the local fair were warned not to use aviation fuel again. It has a different smell to it. Bad enough I can’t hear anymore. Never smoked my lungs are clean. Never wore muffs. I put muffs on the kids when splitting.
 
MooneyPilot

MooneyPilot

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Aviation fuel is called 100 LOW lead. It is not the ethyl lead fuel we used in our cars in the sixties. On top of that, todays engines even chain saw engines burn cleaner than those in the days of “fill it with Ethyl” being said to the guy who pumped your gas for you, checked your oil and cleaned your windshield, while you sat in the car.

A chainsaw BURNS a tiny amount of fuel as compared to the days of 10 MPG 11:1 compression ratio guzzlers. The exhaust from your saw makes up a microscopic, probably immeasurable amount of the air volume that you will be breathing outdoors.

I appreciate the caution exhibited in these posts, but don’t overreact. Consider the practicalities.
 
MooneyPilot

MooneyPilot

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Yes, actually at most airports you can. Don’t try it at a major airport where the Boeings come in, but I’ve flown into small airports all over the South and through the middle of the country. It is no problem walking or driving to the self service pump with gas can and credit card in hand and help yourself.

Most smaller airports are not securely gated at all. Most small town airports are owned and operated by the city and they welcome the fuel business.
 
MooneyPilot

MooneyPilot

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I was mainly thinking about the saws modified with advanced timing. They definitely need something higher than 88. Oh and by the way, aviation fuel is very carefully kept alcohol free.

Apparently discussing fuel is like discussing motor oil or a Ford/ Chevy/Dodge discussion. Opinions are deep seated. I’ve learned my lesson. I’m just pleased that we all have fuel for our saws regardless of what anyone’s personal choice is.
 
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I was mainly thinking about the saws modified with advanced timing. They definitely need something higher than 88.

Apparently discussing fuel is like discussing motor oil or a Ford/ Chevy/Dodge discussion. Opinions are deep seated. I’ve learned my lesson. I’m just pleased that we all have fuel for our saws regardless of what anyone’s personal choice is.
That's how it always is on here. I have learned, run the brand of saw you like, cc's you like, bars you like, chains, sharpen them how you like, oil, oil ratios, ported or not. Use what you like, voice your opinions and let all others slide off your back. Run and use what serves you best and yes Stihl saws are overpriced, with poor support! :cheers:
 
OM617YOTA

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That's a negative good buddy, I'm not running leaded fuel in an engine that I'm holding and which exhausts right in front of me where I'm breathing. There's an enormous difference between running leaded fuel in a car with an exhaust system that vents the exhaust behind you, where you're not breathing it, and a chainsaw that exhausts right where you're breathing.

100LL is only "low lead" compared to 100/130 avgas. By the actual grams of lead per gallon, it's ~2x the lead content of leaded automotive fuel before it was banned. Even if the lead wasn't a flat non-starter for me, there's ethanol free lead free fuel available at gas stations across the country. Look here: https://www.pure-gas.org/

Nope, not for me.
 
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In broad terms, fuels with a higher octane rating are used in high-performance gas engines that have higher compression ratios. Another way to look at octane is that a lower octane number has a faster burn rate. It has a better ability to expel energy faster.
That is what internet says.
 
MooneyPilot

MooneyPilot

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Higher octane fuel burns slower which is sometimes necessary in a high compression engines or an engine with a lot of spark advance in order to prevent spark knock. If you don’t need high octane for that reason there is nothing gained. As long as the octane is high enough to prevent spark knock then there is nothing to be gained by a higher octane.

One problem is that with a loud engine in a small device, spark knock might be there but can’t be heard. That’s why I try to use a little higher octane, for insurance. Someone asked me not long ago why I don’t just drain fuel out of the airplane to mix chainsaw gas. Before that I had never thought about it. About ten years ago my small Stihl dealer who I had massive respect for, recommended 91 octane and Ultra. That’s what I’ve used since then with good success.

When the 100LL was suggested it sounded good because it’s zero alcohol, adequate octane, and for me is readily available.

Sounds like most everyone Here has worked out what fuel works best for them and that’s wonderful.
 
Slotracer577

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Another 100ll user. Purely due to its stability in storage. Another good option is the premixed fuels now available. Personally I use a lot between dirt bikes, jet skis, and saws that its easy to keep a can of mixed gas on hand. Was really handy during the duracho cleanup when people couldn’t get gas from the stations. I had plenty on hand And could have got more at the airport if needed.

I do hate the often repeated myth that octane and flame speed are related. Besides a slower burning fuel can make more power. Also you can formulate high octane and fast burning fuels. Lead alone is probably why 100ll has a higher octane rating. The lead is a great antiknock agent.
 

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