Just wondering if anybody out there has ever ran 104 in 2 strokes or small 4 stroke engines. We finally got a local convenience store that carries 95,100, and 104 non ethanol in 5 gallon pails. I feel safe running 95, and really see no need to go above that, but the 104 is tempting.
104 Octane too much?
- Thread starter Bubster
- Start date
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104 will do you no good in a chainsaw unless compression is 200 PSI or above. Even then, you’d need a few degrees more ignition timing (on top of high compression) to really warrant anything above 100 octane to see an increase in performance. 95 non E will be just fine for general use.
Running a higher octane than you need like 104 wont hurt anything except your wallet.
87 is good enough for 9/10 saws, the hopped up ones might need 91. Small high revving 2 strokes like chainsaws are not prone to detonation like hopped up cars or bikes are.
The only perk to race gas in a saw is for storage reasons, race gas doesnt go stale or gum up carbs.
87 is good enough for 9/10 saws, the hopped up ones might need 91. Small high revving 2 strokes like chainsaws are not prone to detonation like hopped up cars or bikes are.
The only perk to race gas in a saw is for storage reasons, race gas doesnt go stale or gum up carbs.
Being non ethanol is my only reason for using it. I was driving about 40 miles each way for non E gas . Par-Mar stores are popping up everywhere and it is 6 miles away.
That is my go to saw, running 24" full skip.
kshansen
ArboristSite Operative
Only one way to find out…Would that 104 work for my Homelite Super 2?
Maybe put a 36 inch bar on it?
If it is the 2 trigger modelWould that 104 work for my Homelite Super 2?
Maybe put a 36 inch bar on it?
ning
ArboristSite Lurker
Higher octane fuels generally have lower energy value than lower octane. Running 92 in an engine built for 87 is a waste of money and it literally won't perform as well. The only way to get better performance with high octane fuel is to have the engine set up for higher compression and typically advanced timing.
If your saw runs well on low octane, stick with it.
If your saw runs well on low octane, stick with it.
thompsoncustom
ArboristSite Operative
Nailed It!
If non ethanol fuel is on your radar see if there is a small airport in your area. The airport near me sells 91 octane E-free.
91 octane works in just about everything. Also see if there is a marina near your location. Most marina’s sell E-free fuel as well.
That's a load of rubbish higher octane fuels don't have lower energy than lower octane fuels.
Next thing you will be telling us higher octane fuels burn slower
Running low octane or high octane in stock chainsaws the operator wouldn’t even notice a difference between the two that's the reality. That is providing the low octane fuel isn't contaminated with ethanol but if that is case about any e-free high octane fuel will out perform it.
Nope it just burns slower and more controlled
I still have a 68 camaro that motor was 11:1, it got built and is closer to 12:1.
I ran 100LL in it, back when you could pull up to the pumps.
95 in a saw is all you need
I ran 100LL in it, back when you could pull up to the pumps.
95 in a saw is all you need
thompsoncustom
ArboristSite Operative
All depends on what they use to change the octane rating. Vp Fuels has some articles on this matter. It's not that the fuel contains less BTU's just less of the BTU's are actually used.That's a load of rubbish higher octane fuels don't have lower energy than lower octane fuels.
Next thing you will be telling us higher octane fuels burn slower
Running low octane or high octane in stock chainsaws the operator wouldn’t even notice a difference between the two that's the reality. That is providing the low octane fuel isn't contaminated with ethanol if that's the case about any e-free high octane fuel will out perform it.
Quotes from VP fuels website:
Realize first that octane is a measurement of a fuel’s ability to resist detonation—nothing more. The two types of machines used for testing octane—a Motor Octane machine and a Research Octane machine—were designed in the 1930s. They were designed to test for octane numbers from the 0-100 range, therefore, any number above 100 is an extrapolation.
But bear in mind, a fuel’s ability to prevent detonation is a function of more than just octane. For example, VP’s fuels—oxygenated or nonoxygenated—vaporize much better than competitive fuels with comparable octane ratings. This means VP fuels cool the intake charge, burn faster and yield more efficient combustion. As a result, the “effective” octane rating of VP’s fuels is even higher than the rating generated by the octane test. As a result, VP fuels will prevent detonation more effectively than competitive fuels with comparable MONs.
Can you over octane an engine?
Yes you can over octane an engine. Generally you will get sluggish throttle response. Also you may get fouled plugs and deposits in the exhaust ports and headers. When an engine is trying to burn a fuel that has too much octane, the burn rate is incorrect and all of the fuel won’t be used up. This excess usually gets left as a deposit or gets pushed out the exhaust. It is important to match your engine’s needs with the correct fuel.
I used to run 108 leaded in a 4 HP boat motor for duck hunting in swamps. Reason being a three gallon tank might last three or four years. So, I figured right or wrong that even after a couple of years sealed it will still run OK . It did.
retiredfarmer
ArboristSite Member
Lol look at a can of husqvarna gas. The octane is higher than you are wondering about. Wepp that is right from the manufacturer enough said
The more important issue is , using non - ethanol fuel for long term performance , Stihl uses 93 and Husqvarna uses 95 octane in there can fuels ,
A few years back I was also driving 40 plus miles each way for e free gas. My buddies all thought I was nuts but my log splitter and riding mower have never had ethanol fuel in them. Luckily now a Shell station 9 miles up the road sells 90 e free. I just throw a jug in my work van and hit it otw home now. Just grabbed 6 gallons Friday, Much more convenient. Pretty sure my Stihl and Echo stuff says to run 89 minimum.
