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A weedwhacker running ethanol is admittedly a litle pointless. An RC car, plane, or boat would make this combination a lot more fun. Scooters are usually 49cc or above. This 31cc 2 stroke motor is destined to simply be a test mule. Speaking of tests...her first one went over quite well!

 

I mixed an odd concentration of fuel and lubricant. 1/3 2 stroke oil, 1/3 gas, 1/3 E85 was the mixture as it ended up. I admit I had no topend lubricant that is used in 2 stroke engines. Topend lube is recommended whenever alcohol and 2 stroke oil are blended. Dropping some 2 stroke oil into a mixture of E85 (as opposed to gas) made the oil simply sit there in the bottom of the jar. When the mixture blended, the purple 2 stroke oil more or less disappeared. Mixing in more gasoline should give the oil something to bond to. Ethanol would then dilute that mixture. When I combined the 3, the mix turned a very deep indigo blue. This has been done before but I had to improvise without that topend lube. I had hoped by overdosing the mix on lubricant (it's usually 40:1 gas/oil) that there would be enough lube to make the engine happy and not sieze anything. Since 2 stroke engines have to lubricate themselves and burn the same mixture, it was important to have the oil in a more "blended state".

 

The cocktail of fuel and oil was a bugger to start cold. It took a minute to dial in the mixture. A 1/4 turn of the screw ended up being all it needed. When I hit the throttle cold, it would die. The engine was harder to turn over. Pulling the rope took more effort.  After some initial stubbornness, I warmed it up for just another minute to see what would happen. It settled into a relatively low idle for a 2-stroke. There was no blue smoke at idle like usual. Blipping the gas made it rev right up like normal, too. Blue smoke only came at full throttle. This thing used to belch blue and nauseate me. It almost smelled pleasant...for a 2 stroke. The blue smoke on this mixture seemed far more homogeneous. It puffed evenly and disappeared quickly rather than lingering like grandma's after-dinner treat. For a mixture heavily laced with oil, it sure didn't smell like it.

 

The best part of the whole deal was revving that engine at full blast. I've never heard a 2 stroke sound like that. This one also lacked any psecial intake or tuned header. My ears rung for a 1/2 hour when it was done. I ran through the whole mix in a about 15 minutes of wide open throttle. I don't know if it gained any redline rpm, but the sound was so shrill and sharp it went from sounding like an old smoky weedwhacker to screaming like an Indycar.

 

I'm not sure if an ethanol mix compares at all to nitro fuel in the mix. Perhaps this is another alternative to nitro, or something to be tried in conjunction with it. The power, sound, and response was impressive. I handled this weedeater for a good 6 years. The spool sucked after a while, but the engine was fine. It would rip that line out of the spool without much trouble :D. Seeing this for myself, in addition to the briggs testing and both Subarus, I'm sold on this fuel moreso than when I started. Mixed and tuned correctly, you can run it in anything. One disclaimer to improve reliability: run every small engine until the fuel runs out. Storing my motors dry is habit more than anything else.

 

 

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If you want to try something else, try mixing E85 and biodiesel. They mix well and biodiesel has excellent lubricity.  I mixed about 50/50 and got a friend with a glow engine to try it--as long as the battery was connected to the glowplug it ran. I think it would have done better if more E85 was in the mix.

Marty

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You might also try adding canola oil in place of the 2 stroke oil in the normal 2 stroke oil ratio.

 

Canola oil being a vegetable oil should mix with E85, and some of the vegetable/biological oils are very good engine lubricants. (Castor oil is still one of the best except for its tendency to gell after it has been heated strongly ---- they had to drain the engine oil hot in the old Indy cars when they used it in the crank case.)

 

 

Larry

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www.gt-labs.net/video/2stroketest.wmv

 

Here's a vid of this fuel combination I ran. Look how clean it burns. Though it still stinks, the smoke doesn't linger as long as just gas/2 stroke oil. I probably could use less oil in the mixture but haven't tried it yet. I think too much oil might be what's killing it or making it waver at full throttle. It either dies on tip in (lean) or under full load (rich) with just 1/2 a twist on the mixture screw. there's two other set screws physically on top of the assembly that I haven't figured out what they do other than kill the motor even quicker so I leave them alone LOL.

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