Auger fuel question about ethanol

[kb]

I have an older Jiffy model 50/T. It was running perfect then I went on a trip to upstate New York. While I was up there I got some gas that was alcohol free. I did my usual mix with synthetic two cycle oil and filled my tank. While I was out trying to drill holes my auger would start but would die as soon as I opened the throttle. I managed to reetune it using the screws on the carburetor itself and I managed to finish the weekend out drilling many many holes with it.
When I got home I had to refill my tank using my local gas with ethanol and of course my ethanol treatments and synthetic two-stroke oil. Then it ran like crap again and I ended up having to screw around with the gas mixture trying to get it to run with the throttle open.

My question is does the ethanol in our fuel require different tuning procedures to make our engines work?    Has anyone else experienced this?   

[JimQ]

I own/operate an Outdoor Power Equipment / Small Engine Repair business and have to deal with this frequently with small 2-strokes.  At the shop I use ethanol free 87 octane mixed with Opti-2 at 50:1.  When people bring in something that doesn't run, the first thing I do is start with empting the tank and refilling with fresh mix.   After the repair (whatever it is) I will adjust the carburetor so that it runs right.  I let the owner know what fuel mix is in the tank and recommend they use the same.  I also mention that if they use another fuel/oil mix, further adjustment may be required and ocationally they do return for a tweak.  So, I would definetly recommend picking a fuel, picking an oil, decide what ratio you want to run, tune it, and stick with it.

The only other thought I have regarding what you experenced...  Change in altitude?

Q

[cold_feet]

I like Jim Q answers and do not disagree with them. One other note I would add by running Ethanol blended fuels previous to taking the trip chances are some of the damage was already being done to the augers Diaphragm, fuel pump, and needle and seat. I am beginning to believe guys should be ordering rebuild kits for their augers and have 2 or 3 of them on hand and learn how to rebuild these carbs. Seems to me Carbs are more of a issue than spark plugs.  Jim also hit on Altitude which is a huge factor but because these carbs have minimum adjustments to fuel ratio that also is a problem.   Air temps also are issues to deal with. the colder the air temp the more fuel you can burn and just the opposite with warm temps. When we raced cars every 10 deg required a jet change to the carbs. These carbs on these augers pretty much are set and only minor adjustments can be made to the fuel and that's about it.   

[kb]

I use the optio brand oil as well. Unfortionatly I can not get ethanol free fuel around here.

Thank you for your insight. 

[JimQ]

...I am beginning to believe guys should be ordering rebuild kits for their augers and have 2 or 3 of them on hand and learn how to rebuild these carbs. Seems to me Carbs are more of a issue than spark plugs.

Great idea!  I couldn't agree more.  Without exaggerating, I would say 90% or our repairs are carburetor related.  Of the 1000's we've done, I'll bet I could count on one hand the number of times a bad spark plug was the root off the issue.

Don't buy the kits from the auger manufacturer.  Knowing what these kits sell for wholesale, I can tell you the markup is crazy!  Find the manufacturer of the carb (Zama, Walbro, Tillitson, etc), find the numbers on the carb, lookup the kit number on the carb manufacturers site and Google it.  Ebay is actually a pretty good place to find a good price on a kit.

The carb manufacturers also have good service information on their sites.

A few things to keep an eye on during a rebuild....

Make sure you know the order and orientation of the gaskets and diaphragms on both the pump side and metering chamber side of the carb.  Easy to screw this one up.

Compressed air can damage the check valve in the main nozzle.  Once its shot, the carb is junk.  So, know what/where it is and go easy on it.

Make sure the metering lever height is set correctly.  If you get done and it still seems to run lean, you can raise the lever height to give it more fuel.

Don't use carb cleaner unless you have to, and if you do, make sure you know it will cause any rubber needle seats to swell.  This will effect the  float level and metering lever height.

[xjma]

I use the optio brand oil as well. Unfortionatly I can not get ethanol free fuel around here.

Thank you for your insight.

Yes you can, just not at a pump.  TruFuel comes pre mixed with the oil and zero ethanol.  It smells like gasoline used to smell like.  Long shelf life, no problems. 

[dkfry]

The problem is ethanol content can vary quite a bit. Some will have a few % ethanol some over 10%. Ethanol affects the stoich ratio. (ratio of fuel to air) ethanol gas requires more fuel than pure gas. Then throw in cold dense air and a worn/stiff carburetor diaphram and you can end up with issues.

Best bet IMO is to haul gas/oil mix with you when you travel to try and keep the fuel consistent.

[kb]

That is exactly what I plan to do for next time. I will go through roughly 2 to 3 gallons in my auger in the course of a winter.

[cold_feet]

Here is a state by state Ethanol free stations in the US.

Do not worry that your auger instructions claim it runs on 87 octane and much of this fuel is 92.  The 92 will not harm the engine. Stating the engine runs on 87 simply means it can run on a lower octane rated fuel. 

http://pure-gas.org/index.jsp?stateprov=NY 

[JimQ]

Do not worry that your auger instructions claim it runs on 87 octane and much of this fuel is 92.  The 92 will not harm the engine. Stating the engine runs on 87 simply means it can run on a lower octane rated fuel. 

In theory, I mildly disagree.  I'm not a Petroleum Engineer and I don't usually comment on things I can't back up with firsthand knowledge and/or data so keep that in mind BUT...

Here are the opinions that I developed based on what I've read/researched/sometimes witnessed, and believe.


A fuel with a high Octane rating (RON+MON / 2) has a higher resistance to combustion than a lower rated fuel.

In a cool running, low compression engine like our auger engines, this can make the engine harder to start and if used regularly, can leave deposits in the engine due to incomplete combustion.

In the real world where we all live, who knows what you're actually going to get out of the pump.

I've come to the conclusion there really is no perfect fuel solution for our auger engines.  Even the canned fuel is not perfect for our application.  It's essentially a "summer blend" fuel with a low Reed Vapor Pressure (RVP).  That allows it to be stored in a sealed can in varying temperatures without developing too much pressure and keeps the EPA happy too.  Lower vapor pressure can, in theory, make and engine harder to start when cold.

So my personal auger fuel choice list based on the fuels available to me here in Beatrice, NE goes something like this  -

Canned fuel
87 Octane Ethanol Free
89 Octane w / 10% Ethanol
87 Octane w / 10% Ethanol
Premium

Then pick your oil.  I'm not going to touch that subject with a 10ft pole.

10% Ethanol fuel doesn't seem to cause issues when you use it.  It definitely causes issues when you store it and phase separation takes place.  This I witness on a daily basis.

This is a complex issue and everyone has their own opinion.  I've just shared mine.  My opinion could definitely be changed if I could find some credible data suggesting otherwise or learn from someone on the technical side of the Petroleum Industry (not the Sales and Marketing side  ) 

[dkfry]

I always run 87 in all my 2-strokes whether auger, outboards, chainsaw and etc. None of the 2-strokes I own have near enough compression to need anything other than 87. I do spend the $.50+ per gallon extra on pure gas though even in my rather thirsty outboards. Luckily I can get the pure gas close to me. Corn is for eating not for burning.

[cold_feet]

Jim I don't argue what I see either but while we talk the 87 vs. the 92 octane burn rate this is so minimum it will not be even a noticeable difference when you try to start the engine. If you feel funky about it cut it slightly with the 87. You are correct when you say the burn rate is different. Higher the Octane the slower the burn rate.  BUT what is not talked of is the flash point!! Higher the Octane  the lower the flash point thus by all rights it vaporizes faster and needs less spark to ignite.  When we ran a NASCR Modified we ran 120 Octane because with the compression that's the only thing that would build power and even run right. The 87 octane  was developed as a economy fuel and engines we designed to run on this stuff but the slight difference of 87 to the 92 is not significant enough to create a problem starting Vs. running the Oxy fuels.  I understand the storage problems with the Oxy fuels and if anything they engine was drained and run dry after every use the moisture problem would be eliminated BUT the reactions to the diaphragms and needle and seat are still going to be a issue with the Oxy fuels. Until Carbs are built to accept the Oxy fuel blended fuels this is going to be a ongoing problem.  Funny thing to me these Carb companies had ample time to put together a carb and components to run perfectly but yet they have not done a thing about it.

[Rebelss]

It's nice to see some INTELLIGENT input for once!!!  I gave up posting answers/advice about Ethanol; people will believe exactly what they want to, even if ya whop them in the face with facts.
40 years of engine repair has taught me what I need to know. Only thing I'll add, is lower octane, as in 87-88 range, actually has more BTU's of energy than a 93-94 octane. Will you notice a difference between 87 and 91 octane in a small 2 stroke engine? Very doubtful IMO. Happy augering!