Is 89 octane really the best fuel to use?

I run only non oxygenated gas in all my small engines,because I know that it last's longer, and it will not degrade over time. I live in minnesota and you do not ride a bike from October until April if you ar luckey! Bottom line is non oxygenated has a longer shelf life !!!!!!!!!!!!!!!!!!! Done end of debate!

Unless they make small engine carburetors out of something different than what they make full sized car engine carbs out of, I don't understand how it would get any more destroyed than say the quadrajet on my old chevy truck.

Also, alcohol in carbed applications is less a problem than in fuel injected applications. carb you can adjust the richness screw to compensate for the introduction of higher levels of alcohol. engine will run cooler with more alcohol. The big problem comes in fuel injected applications, which use an O2 sensor in the exhaust stream to determine the burned air/fuel ratio. Cooler exhaust is indicative of an overly rich condition, which the engine control module attempts to correct by leaning the crap out of the fuel mixture. this in turn leads to detonation, which triggers the knock sensor to retard the crap out of the timing. eventually, the ECM quits listening to the O2 sensor, and replaces it with a dummy value, that provides a lot less power, poor fuel economy, but will prevent the engine from destroying itself.

Carbs don't do that, and unless the carbs on these engines are made of cotton candy, alcohol isn't going to magically destroy it. Seals get old and brittle on their own from years of service, and eventually all carbs need a rebuild to install new seals. They design these with the idea that they're going to be full of caustic unstable flammable liquids

I'm going through the first gallon I've added Ethanol Shield to the mix with, and it's running great. Ethanol gas burns hotter, and in a car that means you'll foul sparkplugs less and use less fossil fuels. In a 2 cycle engine, you're just running hotter and hotter the higher the octane and higher the ethanol content - which can lead to far worse.

http://www.oscar-wilson.com/IBS/B3C/Ethanol Shield Sales Sheet.pdf
Dailymotion - Ethanol Shield Product Review with Burn Test! - a Tech & Science video

DuctTapedGoat said:

I'm going through the first gallon I've added Ethanol Shield to the mix with, and it's running great. Ethanol gas burns hotter, and in a car that means you'll foul sparkplugs less and use less fossil fuels. In a 2 cycle engine, you're just running hotter and hotter the higher the octane and higher the ethanol content - which can lead to far worse.

http://www.oscar-wilson.com/IBS/B3C/Ethanol Shield Sales Sheet.pdf
Dailymotion - Ethanol Shield Product Review with Burn Test! - a Tech & Science video

Click to expand...

Thats all fine and dandy, except alchol, specifically ethanol burns cooler than gasonline. thers about 60% as much energy stored in Ethanol as there is in gasoline, so running gasoline with 10% ethanol will result in a fraction of a percentage in lowered running temperature, and available power. Additionally, of the 2 liquids, Gasoline is generally the more unstable, and more caustic of the 2. I gave an explaination of why alcohol is thought to burn hotter than gasoline in my previous post, and thats because fuel injection leans the crap out of fuel ratios trying to get rid of what it precieves as a "lean running condition."

Suppose I'll have to prove my point by running nothing but E-85 in my bike once I get it set up...

Good luck rebuilding to have an E85 Fuel Flex bike motor- you're going to have a **** of a time keeping that lubricated. I'll correct myself - ethanol burns cooler, but burns longer - leaving you with a hotter motor. As well, good luck getting your 2 cycle oil to even mix with the 85% ethanol.

Ethanol isn't great stuff to begin with, and ethanol gas shouldn't even be put into a 2 cycle motor.

Castor oil bends well with ethanol and methanol. Lubrication shouldn't be a problem.

My bikes seem to run better with 91.

Dave you are correct i test 93 octane fuel in my engine with 150 psi of compression and dont have power the engine loose the power the same day in a long ride with my friends one bike is down and the fuel is transfer to my bikethis fuel have the same oil mix but have 89 octane when i turn on my engine and up the first hill i feel the power again..

2 strokes with BMEP of 125-150 should burn the higher octane. Also.. Mixing lowers octane.. Enjoy the ride..

Great thread.

Thanks for all the input. It seems safe to drop down and avoid ethanol mixes if any one is concerned from what I read.

I mistakenly thought more octane would be better but now I know better. Next buy will be regular.

Using Lucas oil at 24 to one with 200 miles on the motor. Any suggestions are welcome since this is all new for me and highly addictive!

Oh I'm hooked and bad.

Another thing to add is that a proper working expansion chamber will also raise the compression.

I run good old "regular" 89 octane and Castrol 2 stroke at 20:1 first for break in, then 89 octane and Synteck at 80:1
Haven't seized one yet.
FR

exhaust changes the compression, good one. you may be thinking of backpressure...

Here,s where I am at ,I live in Minnesota , and our riding season is greatly shorten'd due to the extreme season's. I do not like ethanol, as a small engine fuel period... It gum's up the carb's in my small engine's over the long winter!!!!!!!!!!!!! Dude from Wisconsin should agree! Octane is not the issue, the unstable ethanol is.

not to back track...but....when I was young I had a honda 400 4 cylinder motor cycle...and 87 octane would top out at 75 mph...high test would do 90....just always figured little engines need all the help they can get...since that experience anyhow.