Using 105 Octane Gas In A Chainsaw

Dear All,

I have a new Husqvarna chainsaw. The dealer said NOT to use fuel over 95 octane because it will run too hot and hurt the engine. Another dealer suggested several times that I go to the local airport and get their gas (no ethanol, 105 octave) to which I can add the proper ratio of oil and that it will NOT hurt the engine.

Do you have any experience with this?

Thanks for your time.

ML in MD.

I've heard of people using it but mixed 1/2 w/ 87 oct. strait up will burn your saw up for sure. can use trufuel if you want ethanol free but its not cheap. then again neither is the av gas!

I think the second guy was telling you that not because of the octane, but because of the ethanol.

I'm lucky i live on the canadian border. their 93oct. is ethanol free. with the exchange and can. tax its about $4 american a gal. worth it to me as i don't have to treat it and its good for a year before it starts to degrade. trufuel or similar ethanol free would be my next choice. ethanol in gas sucks! esp. in the cold weather up here!

Premium gas here doesn't have ethanol and it's the only thing I'll use in any of my small engine equipment. Ethanol truly does suck. I have had it gum up more carbs than I can count and makes me very angry to have to rebuild a carb before I can use my equipment that sits for any length of time.

i feel your pain! cost me one blown chainsaw and over a $1000 spent to mechanics to get my other equipment running again! not very mechanically savvy unfortunately.

Octane rating is more of a measurement of how fast a fuel burns and the auto-ignition temperature. The higher the number, the slower burning/higher auto-ignition temperature. Many people think high octane means hotter or more powerful and that isn't quite true. It is capable of being used in a higher compression engine without reaching auto-ignition (pinging, detonation) which means you can make a more powerful engine (higher compression ratio - higher performance), but it doesn't work magic on an engine vs using lower octane rating (note: rating, pure octane is supposed to burn at 100 and the rating compares the gasoline to this, depending on the testing method of course).

Using fuel with too high of an octane rating would be more likely to cause incomplete combustion which would mean more pollution, more deposits of unburned fuel sticking to components, and lower combustion temperatures. Having these deposits build up can cause engine problems, and cause the engine to retain heat if you do get the engine running hotter using a lower octane rating fuel at a later time. I would look up the specific information for the engine online and follow those guidelines. Going with fuel that has a slightly higher octane rating will likely only have the negative effect of being more expensive. Going with too low of an octane rating can cause pre-ignition/pinging/detonation and bust the piston or other internal engine parts.

If you have a race track or drag strip near you then it might be an idea to look there for ethanol-free fuel. Ethanol increases the octane rating of fuel, but it and other additives can have drawbacks such as being incompatible with certain fuel systems and causing damage, not as friendly to being stored for long periods, and problems in extreme temperatures. It honestly might be cheaper to offer some of your fuel to a neighbor and go through it more frequently than to have it sit around for a few years and damage your equipment. Being certain to empty the fuel system before extended periods of storage/non-usage will help keep the fuel system clean.

We just buy the quart of fuel at Lowes.

Dana Jones wrote:We just buy the quart of fuel at Lowes.

thats your safest bet if you don't have access to ethanol free gas.

Micah:

I have been investigating fuel, repair issues and various brands and types of chainsaws for several weeks now and your post brought up an option I had not yet come across. I wonder if you have heard of the website: pure-gas at org which helps people locate stations that sell ethanol-free gas? Finding a station within easy driving distance of us in WV and PA should make a huge difference in the amount of fuel-related issues we have with our small engines from now on! I hope you can find a location that is reasonable for you. Using ethanol-free gas will save you a pile over pre-mix by the quart.

Good luck with your chainsaw! What model did you settle on?

GG

use the fuel the manufacturer specifies. Using a lower or higher rating will not aid performance. A lower octane may destroy your energy, and a higher octane is just a waste of money but will absolutely not burn hotter or give more power.

I don't have access to ethanol free fuels that I would use in my small engines.
What I do is treat the fuel to stabilize it then I use 1 gal. and 2 gal. containers for mixing the oil and fuel.
In the three years I've been doing this I have not experienced any issues.
I do this for my boat's motor as well and I have not had any issues with it either.

I have access to AV gas both green and blue but the only thing I use those in is my Jeep with a High compression engine, it simply runs better and gets better mileage with the 100 oct. (green) fuel.
The blue (110 oct.) fuel runs just fine in this engine but it is a bit of overkill since my compression ratio is only 12:1 110 octane is really for 14:1and 15:1 ratios .

I had a friend that wanted to get "Jet Fuel" for his automobile. I had to tell him that I didn't think his vehicle would like kerosene to run on.
I flew fighters in the Navy, most people have no idea that "Jets" run on kerosene not gasoline.

Gene Green wrote:Micah:

I have been investigating fuel, repair issues and various brands and types of chainsaws for several weeks now and your post brought up an option I had not yet come across. I wonder if you have heard of the website: pure-gas at org which helps people locate stations that sell ethanol-free gas? Finding a station within easy driving distance of us in WV and PA should make a huge difference in the amount of fuel-related issues we have with our small engines from now on! I hope you can find a location that is reasonable for you. Using ethanol-free gas will save you a pile over pre-mix by the quart.

Good luck with your chainsaw! What model did you settle on?

GG

i run a husquavana ! i don't have a ethanol free option unless i go to canada. ethanol bites!

I run 100 octane with a bottle of mix in my chainsaw.
It requires a 97 octane but couldn't find it. However I could find 91 and 93 but saw acted funny cranking. But bought a can premix 97 octane and ran fine. 100 Octane hasn't hurt my saw yet and fires up. Plus I only pay $5.85 a gallon. Where one can of premix was $15 a quart.

Hi Nathan,

Welcome to Permies.