Corn Fuel Issues?

Me personally I use aviation fuel. We have a Stihl dealer here in town that sells it or you can go out to the small airport and get it youself. I use it in all my small engines and never had any storage (never use stabil) problems with it. When I get it I put some Marvel Mystery oil in it (not sure if it work the same as stabil or not). And then mix with Amsoil 2 stroke as needed for my saws. I am not exactly sure what the octane is but it's higher than what you can get at the pump. The saws seem to run a better than with pump gas but you need to re-tune your carb.

I have a Stihl ms661 (with the auto tune carb) and was having some problems with it not wanting to start after it ran out of gas. I took it to the dealer they dumped my gas out and put in regular pump gas in to do their tests. Long story short. It needed a new mixing fuel solenoid. When I got it back it had the pump gas still in it. It ran very sluggish! I ran the tank out and put the aviation gas in and the saw seemed to wake up a good bit! Coincidence I don't know? If anyone has any info on what I am saying is wrong please enlighten me!

 

The mtronic takes a little while to get used to the fuel. It took almost a whole tank in the 550 auto tune to get it to run right when switching fuels with that big of an octane difference

 

Cool thanks for the info. But does it actually make it run better? It seems to for me even in my older saws! Or am I just imaging things?

 

I've never got better performance from real high octane. Could be in your head or the fuel isn't that good where you're at.

 

There are lots of fables about high octane fuels.

High octane does not mean higher energy, in fact in many cases the opposite is true. For example, 87 octane autogas contains 125,000 BTUs per gallon, avgas contains 120,200 BTUs per gallon, about 3% less. Or an extreme example, ethanol contains 84,600 BTUs per gallon, and an octane rating of 129! It's the highest octane of the bunch, but lowest fuel energy. Gasahol (10% ethanol) is about the same as avgas regarding BTUs.

So why do some high performance engines use ethanol? They are built to run on the edge of detonation, with high compressions, blowers, etc. They are not designed to be useful daily engines. Without the high octane that the alcohol provides, they will destroy themselves in very fun ways to watch!

Aircraft engines use avgas for safety, not for performance. Most of them run fine on e-free autogas.

Back to the chainsaw - sssuming the saw is properly tuned ... you will get more power from ethanol-free mogas than avgas or gasahol, because of the higher BTUs. If the engine is not on the edge of detonation (which it shouldn't be), the lower octane fuel is often better and nearly always cheaper.

 

Thank you for the info I really appreciate it! I never knew that about the octane and the btu differences!

 

Wow, lots of incorrect information here.
Spark plugs were all designed to run on leaded fuel. Spark plug technology hasn't changed in many years. Airplanes consume hundreds of gallons of fuel to get minor lead deposits on the plugs.
Lead actually was added to gas to slow down the flame front in large bore, low reving (2,000 rpm max, due to prop tips going super sonic above that speed), aero engines, giving a longer power pulse. It also works to reduce detonation in the higher compression aircraft engines (not the ones that can use auto gas)
Since I burn 10 or so gallons a season I'm really not worried.
Besides, my saw plug is cheap, compared to $25+$ times 8 or 12 on an airplane.
I like to put a new plug in each season.
The old plug is never fouled by lead.
Lead will not kill you, it really only is bad for growing kids.
It is the best source of non ethanol fuel, and at free, can't be beat.
I also run 100LL in my snow blowers, lawn mowers, splitter, generator, etc and never have issues with starting after sitting for a year or more.
Besides, I think avgas with two cycle oil smells heavenly.

 

??????????? I am not too sure what to think now?

 

Well, we can go back and forth on the finer points, but in the end you will remain convinced of the value of avgas in saws, and I will remain unconvinced.

I agree that avgas tends to be more stable over time, that is a plus for using avgas. Free is good too, if you got it.

But the saw likely will not run better on it, as it does not need the detonation protection. It will probably run inperceptably worse due to the 5% lower BTU rating.

 

Avgas contains lead, lot of it. Lead is poisonous especially to children, but also to adults. Symptoms and causes - Lead poisoning - Mayo Clinic

Avgas is highly unlikely to make your saw produce more power, it will probably produce less power. It might (likely will) store better. There are other ways to make the saw store better, if that is a problem.

These are indisputable truths. Your call.

 

Well then......

Thanks all for all the comments, and differing opinions.

Maybe, I'll try a 50/50 mix of E10 and no E, with the appropriate amount of fuel stabilizer. That will give me, effectively, E5. I have to think that's better then E10, and the 110 octane will be tamed a bit as well.

I don't go through a lot of gas, between my chainsaw, lawnmower, and snowblower. So, I'd be looking for a bit of extended shelf life. Not months and months, but weeks and weeks should suffice.

Thanks again and Merry Christmas. Everyone have a safe Holiday season.

 

Really if you use less than 10 gallons a year it may be cheaper and easier to buy trufuel or VP SEF in 5 gallons pails.

 

You make it sound like lead was created for use in gas for airplanes it wasn't.
Lead can kill you and cause several types of organ failures.
Lead is an octane booster it slows the rate of burn.....
It resists pre ignition and detonation...Caused by heat and compression..
Lead being added to gas had if I remember correctly little to do with modern airplane engines.

I've redneck tested e85@105 octane. Its hard to ignite on the ground....87 pump is volitol! You get that whhhooomp! E85 it's a cool low slow flame.

Pre 2003 alot of candles were lead core(some still do) and dispursed lead vapor into enclosed spaces like a living room or bathroom.....It was more common in earlier years as well.........
But now they use other poisonous heavy metals like zinc in candle wicks lol.

 

E85 you need about double the fuel volume over pump gas to make the same power.

 

Truth ^^^
High octane fuels is one of the biggest scams perpetuated by big oil companys. Think about it, fuel that burns cooler and slower (read less MPG) sold at a higher profit...

 

When running e85 I never came close to double. On forced induction making more HP with e85 than premium, I was using about 28℅ more fuel at WOT. For rough tuning a good starting point is 30% richer either carb or fuel injection.
Theoretical max power rich is waaay to rich.
I used to have cruise AFR set to 16.8 with e85.....