AV Gas

[SliverPicker]

If your compression ratio is high enough you will get more HP using AvGas. If your compression ratio (which varies with distance above sea level) is not high enough you will not get more HP. The lack of fuel related maintenance /failure using the AvGas may make it worth using, however. I have 6 motorcycles and various other engines to deal with. Without making a short story long I vote for fewer fuel issues. We are all being robbed with this E10 GARBAGE.

PS Using "stabilizer" with ethanol laced gasoline doesn't and can't work.

 

[toolmaker]

Hey guys, thanks for the replies. I opened my account on this forum several years ago when my chainsaw usage was a LOT more than it is now. My life has changed and I don't use my saws nearly as much as I used to use them. I LOVE running a good saw, could do it all day long.

At any rate, I am at the point now where I want to just give my saws the best care that I can, and do what I can to keep them in top shape for as long as possible.

I understand the arguments above from several of you, performance or not, more HP or not, it's six of one - half a dozen of the other. What I think you can all agree on is that the biggest benefit of AV Gas is that it does not contain ethanol. We all know that ethanol is bad, and to stay away from it when possible. Here in Central. Pa., there are no gas stations that I know of that sell ethanol-free gas. that being said, I will buy the AV Gas a couple gallons at a time, keep it in my saws, and hope the seals and diaphragms don't rot out.

SliverPicker:
Your comment about stabilizer doesn't and can't work........................please explain.
I was under the impression that there are several stabilizers that work well with ethanol-laced fuel. Marine grade Sta-Bil, Seafoam, Startron, etc.....

 

[SliverPicker]

The problem is that what happens to the ethanol gas is molecular. The stabilizer can not stop this process.

Nutshell version: The ethanol in the gas directly absorbs water from the air. Over time this mixture goes through a process called "phase separation". The gasoline, water and ethanol separate from one another and can not be remixed. You can test this. Take some E10 and put it in a standard plastic gas jug. Let it sit all summer in the container. In the winter when it is below freezing go give that jug a good shake. You will hear a water iceberg in there knocking around.

If you have any engine with ethanol laced gas in it don't let is sit more than approximately 4 weeks (less in hot weather, heat speeds up chemical processes) of you are asking for trouble. Drain the fuel tank and run the engine until the carb is empty and you are safe. Otherwise you WILL eventually have expensive problems.

Another myth is that running a 2 stroke completely out of gas is somehow bad for the engine. Perhaps it is if the engine happens to be severely over heating when it runs out of fuel. Well over 90% of the oil in the gas does not burn. It is expelled from the engine as tiny droplets. If the oil burned it wouldn't do its job. So when you run the engine out of gas the cylinder etc. is still coated in a film of unburned oil. The engine at the same time it runs out of fuel quits producing heat No problem.

 

[HuskStihl]

If your compression ratio is high enough you will get more HP using AvGas. If your compression ratio (which varies with distance above sea level) is not high enough you will not get more HP. The lack of fuel related maintenance /failure using the AvGas may make it worth using, however. I have 6 motorcycles and various other engines to deal with. Without making a short story long I vote for fewer fuel issues. We are all being robbed with this E10 GARBAGE.

PS Using "stabilizer" with ethanol laced gasoline doesn't and can't work.

Higher octane won't make more power in a saw regardless of compression unless you shave the flywheel key and advance the timing to a point that the cheap gas detonates and the fancy gas doesn't. Even then, due to the relative lack of detonation issues in short stroke 2-stroke engines, there may not be that much difference.
There will hopefully soon be a dyno test comparing 110 to 87 in a ported saw in the chainsaw forum, which will be interesting.

As an aside, I own a ported 288 with 230psi which runs great on regular pump gas.

 

[jomoco]

There's good reason neither Stihl or Husky recommend running 87 octane gas in their saws mate...

http://www.stihlusa.com/products/oils--lubricants-and-fuels/

jomoco

 

[mdavlee]

Higher octane won't make more power in a saw regardless of compression unless you shave the flywheel key and advance the timing to a point that the cheap gas detonates and the fancy gas doesn't. Even then, due to the relative lack of detonation issues in short stroke 2-stroke engines, there may not be that much difference.
There will hopefully soon be a dyno test comparing 110 to 87 in a ported saw in the chainsaw forum, which will be interesting.

As an aside, I own a ported 288 with 230psi which runs great on regular pump gas.

The test was done already I believe. I did timed cuts with the 550xp and let it relearn itself between 93 was 10% faster over 3 cuts than 110. I didn't have a jug to put 87 in and test.

 

[slowp]

Yeah, and when your new fangled computer controlled saw won't start?

And your're trapped under a shoreline felled log, and the tides risin?

Henry Stamper's son gonna save yu givin yu mouth to mouth?

Some guys just never give an inch!

jomoco

I think you watch too many movies. We can't log that close to shorelines anymore. We have laws and rules protecting shorelines and riparian areas. That's a non-problem.

 

[SliverPicker]

HS, exactly what I said.