Hey there and welcome, particulary to the fuel section.
Was going to do the quick answer to start with, but looks like I've gone ahead with a bit more anyway!
Right on what's been said so far, issues of fuel production volume, cost/time/effort, feedstocks, stillage etc, and fuel line materials, jetting, corrosion, damge etc, really do apply.
What's your aim with the generator? A test bed to play around with, or a longer term more serious application if things go well?
*Some* advice at this stage can depend a bit on what the aims and present progress are.
Let's break it down a bit;
Desired goal/s. What they are... small, big, play, longer term intent/self sufficiency, sustainability etc.
If homemade fuel, suitable feedstock, and method of use or conversion if starchy.
Space/land available.
If small volume, costs using bought feedstocks such as sugar, corn etc, and heating from lpg, NG, electricity etc may be bearable.
Waste feedstocks or cheap crops, and waste wood firing could (would!) make it a better deal in larger volumes, as Husker has said.
Means of disposing or reusing stillage, by-products etc.
Affordable energy cost for volume desired.
Equipment, feremters, still etc of appropriate size (or sizes, more than one size is useful, small volue testing is an important step.)
Any fuel/beverage ethanol >= 80% being made at present?
Even if the goal is to make your own fuel (or already doing so) it's certainly possible (even preferable) to start testing with some denatured industrial alcohol first.
That can save a whiole lot of effort, and provides a usefulbenchmark. It will be pure (apart from denaturents), and is more than likely to have a favourable pH compared to homemade stuff, unless the homemade stuff is processed in a certain way, and this helps reduce reduce potential corrosion. It can also be diluted to simulate hydrous fuel, useful for testing, and determining designs, desired proof/reflux ratios, output, and energy useage for the fuel-making process.
For a start, if info has been a bit hard to get hold of, pay a visit to these sites at least, have you seen these?
http://running_on_alcohol.tripod.com/id26.html" onclick="window.open(this.href);return false;" rel="nofollow
This covers alot of basics. Have a look at carbueretted vehicle conversions info, it will tend to apply to a generator too.
Main jet, idle jet, mixture settins, ign timimg, these are the basics, esp for basic motors.
Efi is also good to look into, but understanding basics first is a better way to go.
http://tech.groups.yahoo.com/group/alcoholfuel/" onclick="window.open(this.href);return false;" rel="nofollow
Yahoo Ethanol Fuel Group. Alot of well informed people here, but do some "homework" first before asking really
elementary questions, you'll get more from the experience.
Also see if a local library has a copy of "Alcohol Can Be a Gas" by David Blume (or purchase a copy), there is so much useful information in here, a very full picture.
This,
http://www.ornl.gov/sci/bioenergy/pdfs/ ... Blends.pdf" onclick="window.open(this.href);return false;" rel="nofollow
may be useful too. Full title is "Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Engines"
A bit technical/detailed, but is good in that it covers vehicle and small engine testing, such as generators.
Although it only covers blends, some similar issues to E85 and E100.
I've only skim read it at this stage, so not much help on contents unfortunately, but like what I've seen so far.
So, if not already, gain a bit of understanding of the differences and combustion issues/engine requirements between straight gas, E10, E85, and neat alcohol etc.
Ethanol and methanol have been used as high octane racing fuels since tmie immemorial, if you have access to any racers on two or four wheels, or visit speed shops, there could well be someone with good experience/knowledge.
Beware of anecdotes/procedures though that tend to only apply to racing or methanol, because of the difference between that activity and everyday uses. Some things that are fine in racing, are not for the street, and vice versa.
Next plan of attack if going ahead, is to source as much info about target generator as possible, Maybe choose a motor/generator that doesn't matter too much if things go wrong!
See what needs to be modified or changed, and how to return back to normal if that may be required.
Look at the materials used in fuel tank, line, any taps, in the carby, and replace all nitrile o-rings or seals with alky resistant viton, and plastics, fuel lines etc with alc compaible materials.
If nec on model of genny, modify ign sender unit so that the timing can be advanced.
Source required spare parts so that you can keep originals to swap back in. A spare carby, manifold and spare jets to modify is a good move, A "hotter" plug, or a choice of ranges is also a good move.
In the long term, a synthetic oil may be suitable, or frequent checking/oil changes. Pay to keep an eye on this.
A cold start method is also very useful, if not essential. This could be as simple as starting on gas to begin with,pre- heating the fuel or manifold in some way, or a spray of engine start, or an lpg vaporisor, which is *very* handy.
Some larger generators such as Cummins have an lpg kit as an option, and I can highly reccommend it. A proper manual choke is almost essential. Electric start is good, because while getting things right, pull starting can be a road to frustration. Getting things hot and up to running temp first on another fuel is the best way to start with alcohol, get this right, then rich cold running can be worked on.
Other useful items could be an auxiallary alcohol tank and tap, again this saves frigging around with standard stuff to start with, if it's compatibility is in doubt.
Extras if money is available to splash around, or loaners available, would be an Exhaust temperature gauge,and a wideband O2 sensor/gauge. A generator is like a poor mans dyno, so with a range of loads from zero to full, and if a mechanical or electrical throottle position sensor is also added, a good gas benchmark can be obtained, and the information and tools available to better judge mixture settings, performance and emissions on alky.
Another good move, especially for homemade hydrous alky, (but for any kind if fuel pumps are involved), is an anti-corrosive/upper cyl/fuel pump lubricant additive. Redline make a couple of specialised products, one specificaly for 2-stroke alky fuel (but fine in the small qtys only required for this kind of app), and a specific alcohol fuel additive. Castor oil can also be used, and while it smells good, unless it's a specific automotive product such as "Castrol-R" or the Redline alternative, some gelling, dropout, etc may ocurr in fuel stored long term/left in carby. It shouldn't be a problem in the combustion chambers in the small qtys used for this ap though.
It's also a wise move to drain the carby at the end of each batch testing, some carbs are made of cheap material that
homemade hydrous fuel in particular like to coorode and gell. Brass and copper too can be affected, and some plastics, so this checking comes under the materials compatibility checking and rectifying, esp for long term, reliable. use.
Jetting will require some pin drills in a wide range of sizes, and maybe some solder and an iron to take things back if holes get too big! Micrometer can be handy to double check pin-drill sizes, easy to lose track of size of a dozen or more small drills. They also make useful gauges for measuring existing jets.
It all depends really on what the aim is, small, simple mororbikes also make a good item to play around with.
Generators, tending to be low comp etc, may well be quite thirsty on Etoh, unless manifold heating, or even vaporisation used.
I'm messing around with a 24HP Cummins/Onan, 980cc horizontal twin generator, and an old TT500, both a real hoot, but quite thirsty on the alc with only jetting and ign timing to vary. The Cummins is particularly thirsty as I haven't delved into the ign timing capability yet.
With the hassles of jetting and ign timimg, and both projects not yet sorted (although I'm going to have another crack at the TT before taking it back to standard), Efi is really the way to go. Now planing to use the Cummins, and a smaller less valuable bike, and a cheap old efi car as testbeds for a "Megasquirt" build. This Diy ecu is well supported, can support all manner of fuel and ign maps depending on the version, and can do real time tuning. That's flexibility!
In the Megasquirt forums, people have converted all sorts of things to Efi, from tiny four strokes, Briggs and Stratton V-twins, to Deloreans, so if the interest is there to take conversion a bit further, thers' certainly some info out there, and going from carb to Efi/Gas with a tuneable Ecu, is a step towards Efi/Ethanol, or conversion from factory ecu to tunebale ecu
I'll be posting more on this when I've had some time to assemble and test the unit, and have something more to report.
Hope this useful/interesting.
