E17.5 90 + octane experiment

Geo-TH,In

Well-known Member
I'm trying to remove carbon form a 20 hp kohler command that has 1500 hours. The engine doesn't use a drop of oil. It has always run rich, especially when carb needs cleaning. I've used a hotter plug, only to have it diesel, run backwards, when it been run hard and I turn it off.

There is absolutely no carb adj. Started the experiment with new air filter and using e15 blend, 88 octane.

Last tank was a E17.5 90 + octane blend. I use 1/2 gal e85 and 4.5 gal e10 89 octane. Final cost is about $.05 more per gallon.

Well the spark plugs look better than the spark plugs in my Kaw 4010 EFI mule which only has 130 hours. Looking through spark plug hole, I'm seeing less and less carbon build up on piston. In places I'm seeing the aluminum poston.

This time while I had the plugs out, I decided to use my HF spark plug cleaner. Next tank, I'll pull plugs and post a pic.

So far so good. No hole in piston, no carb or fuel pump failure. No noticable loss of power. Engine runs good. I do notice a need for a small amount of choke for about the first 15-20 seconds, which in the past no choke needed after it starts.

I'm convinced I headed in the right direction, pending a hole in piston, e17.5 harming the carb or fuel pump.

After another 10 gallons of e17.5, which Ive already blended. I plan to pull plugs, take a pic. I may go back to e15 blend to see what happens. Kinda of wish I had a camera to take a better look and see inside cylinder. I think I may be taking a trip to HF soon.

Has anyone used a cheapie camera from HF?
george
 
It's obviously not running lean so detonation and burning a hole in the piston is unlikely.
It's strange that an emissions engine would be shipped from the factory running over rich.
Is the engine lightly loaded or heavily loaded?
 
George have three off the HF cameras. Catch them on sale for 69 bucks and use the 20% coupon makes them reasonable. Got about 21 air cooled engines here and never have a lot of gas problems that some folks sweat they have. We run e 85 if I pick up a weed eater or chainsaw that has not been run in awhile I will dump the gas but other than that just pull and go.
 
I don't think it's strange it was shipped from the factory running rich. It wasn't right from the factory but with the emission requirements it can't be adjusted to compensate for a production variance. This happened a lot in cars when we got heavy into emissions carburetors. The whole idea we can build an engine, adjust it ONCE and it'll never need any adjustment ever is insane. Thankfully cars evolved into feed back fuel injection that adjust themselves.
 
Try using 1 oz. of Marvel Mystery Oil per gallon of fuel. Always used to have problems with small engines until I started adding it to the gas. No more problems.
 
So is your thinking the ethanol is helping or the higher octane from the ethanol is helping?

Since E85 can be as low as E51 and still be called E85 it is real hard to get a precise octane rating.

a167384.jpg


Then we factor in that most quote E85 as having a octane rating of 105 to 115. Some say that is wrong.

a167385.jpg


So if we assumed your E85 was really 85% ethanol and took the octane rating of 95 we would have.

89 x 4.5 = 400.5
95 x .5 = 47.5
47.5 = 400.5 = 448
448 / 5 = 89.6
So your new octane rating is 89.6

I do not think you will have a problem with to high of a octane.
Higher ethanol content eating the fuel system from the inside out might be a different story if you keep pumping the ethanol to it in greater quantities.
 
I have used water to do away with carbon deposits.
Here is an article . Do search for many more.

https://en.wikipedia.org/wiki/Water_injection_%28engine%29
 
Check the PH of the E-85 your using. Most of the fuel system problems everyone has experienced come from ethanol being produced at a low PH (around 4.25) making it acidic. When it sits and absorbs moisture from the atmosphere in humid conditions, it can create a mild form of sulfuric acid. The ethanol plant I work at mad a correction to their process years ago to bring the PH of the final product to a neutral PH to help cure this problem. Not all plants have done this, and there is no way of telling where your ethanol came from so check that PH.
 
rev it up to a medium range and fed it slowly a auto transmission fluid through the carburetor intake . it will be smokey but it takes all the carbon away .
 
start without choke, fouling of plugs, carbon buildup all point to a rich carb setting-and you have the "sealed" jet carb that can"t be adjusted. The Ethanol mix you"ve been experimenting with has "leaned" your fuel mix enough that it has gotten to what the carb should have been originally- ethanol is a "oxygenate" from the OH radical replacing a H ion in the carbon chain. SOME sealed carbs were set for sea level jetting, tested in a near Washington DC EPA lab and passed- get up 1000 foot above sea level and a bit rich. That seems to be what you have, you"ve got a working fix, may as well continue. RN
 
Just make the jump and run a tank of straight E85. It won't hurt anything, had one running on it since '07.
 
buickandeere,
I like to error on the side of caution, so that why I spend a few pennies more on 89 octane. Correct me if I'm worng, I thought the EPA required e10 to clean up the air and make cars run cleaner. My thinking is that boosting the E rating to 17.5, or whatever it is by adding 1/2 gallon e85 to 4.5 gallons of e10, will do two things, lower the combustion temperature and increase the amount of oxygen during combustion leaning down the fuel/air mix.

I think my e17.5 is doing just that. The only way I currently have to tell things are improving is by looking at the carbon on the plugs and the carbon on top of the piston is going by-by.

I read someplace that adding oil to gas could lead to detionation, which could lead to holes in piston.

I don't like the idea of adding water to a hot engine. I once lost a 3.5 briggs engine because a large chunk of carbon broke off, got wedged between piston and cylinder and put a major grove in aluminum cylinder wall.

Besides using something to decarbon, really doesn't fix the reason why carbon is there in the first place. I'm looking for a way to lean thing down when I have no carb adjustments.

What's your thoughts? An I heading in the right direction or heading to small engine warehouse to buy a new engine?
george
 
Thanks for your input. I bought a used 2004 terramite T5c when it had 435 hours on it and it was 4 years old. When I got it, the left plug was conpletely fouled out. Replaced plug and it ran fine. Some said I had a head gasket problem. Compression test was good, Leak down test was good.

The guy at the small engine shop sold me the next hotter plug, but the left side still had an issue.

Then I discovered the carb needed cleaned. That helped a lot, but engine was still making carbon. Hotter plug caused it to diesel, run backwards. Probably the carbon build up increased compression a little.

All the snake oil ways to remove carbon wasn't that appealing to me, even it they worked, it didn't solve the problem, too rich.

That's when I decided to try an ethanol mix to lean it down. Went with a higher octane, just in case things may get hotter and pop a hole in piston. I also went back to the OEM cooler plug.

Early results show it working. Using 89 octane is within my retired budget. By mixing a gallon of e85 to 9 gallons of 89 octane, I'm saving $.60 using e 85. and 9 gallons of 89 octane is costing me about $1.20 more, so total increase cost is about $.60 for 10 gallon blend. It might crimp my style a little, but worth it to have a clean burning engine. Hoping to extend the life of the girl. Some say 1500 hours on a kohler 20 hp command is like running on borrowed time. I don't think so. Engine is rock solid.
 
Threw the water in humid air.
As the temperature of air changes the amount of water it can hold changes.
This condensation normally settles to the bottom of the gas can unless you have ethanol gas; as ethanol attracts water and can hold it suspended in the gasoline.
 
George, I don't understand why you bring octane into the discussion. Unless you happen to have a variable-displacement test engine, you can't accurately measure the octane of your mix. At any rate, the actual octane is pretty much irrelevant in your Kohler engine, which is designed to run on regular gas. And if your intention is to clean out the combustion chamber, I'd think if anything you would want to go with a lower octane.

You also don't know precisely how much ethanol is in your mix. E85 can contain UP TO 85 percent ethanol, but it can be and typically is less. Likewise with E10. So it might be that winter grade E85 has less ethanol in it than your mix of summer grade E85 and E10.

OK, so your real intention is see what happens when you oxygenate your fuel. Yes, I'd expect the oxygenated fuel to burn a bit cleaner. But aren't you also lowering the combustion chamber temprerature with your gasohol, which defeats your purpose of carbon removal?

Auto manufacturers have struggled with carbon deposits, and their solution has been "Top Tier" fuel, which is certified to have a certain level of detergency. Maybe you should give that a shot.
Top Tier Gas
 
MarkB_MI,
I just went to 89 octane as precaution to prevent the possibility of pre-ignition, detionation.

So what if I got the actual octaning rating wrong? I read someplace that adding 5% ethanol boosts the octane 1 point. So again, I think octane rating is irrelevant, I have 89 + octane instead of 90+.

My goal is to lean out engine, not make carbon, and it appears to be working because I'm seeing less carbon on piston and plug.

Snake oils in fuel have never worked. As for top tier fuels, I use marathon, King Richard claims there is something in marathon gas.

So who sells top tier fuel? Most of the fuel in my town comes from the Marathon refinery.
george
 
Detergents in gasoline are hardly "snake oil". You don't have to take my word for it: GM, Toyota, Mercedes and several other manufacturers say so, which is why the Top Tier spec exists.

Here in Motown, Marathon also supplies much of the gas sold by many different brands. There's a Marathon refinery down in Detroit, so it makes sense. But that is not to say that the gas you buy at a Marathon or Speedway (owned by Marathon) station is the same as that sold by other brands that may actually come from the same refinery. Each brand has its own additive mix. Shell, BP and Mobil all have Top Tier-certified fuel. Marathon and Speedway do not. Why would Marathon bother adding detergents to their fuel beyond the minimum required by the EPA?
 
Mark,
My choices are limited to shell and marathon. I use marathon. Shell is a greater distance. I'm going to continue my ethanol experiment, marathon gas hasn't worked in the past 6 years. Ethanol is working.

In the winter, my Jubilee carb has to be richened by two full turns on main jet or it will stumble under load. If the kohler has an issue with colder winter air, which it hasn't in the past, I'll reduce the ethanol ratio.

Ethanol is the only way I've been able to lean down mix. Been thinking of a way to determine if I'm lean of peak, but measuring temps on an engine I only operate at half rpms won't work. Buying an O2 sensor for exhaust is over budget.

So monitering plugs and looking at top of piston is my only way to see what's going on inside engine.

Have you a better cheaper way to do it?
george
 
(quoted from post at 10:41:01 08/31/14) Have you a better cheaper way to do it?
george

Of course, everybody does but you dont seem interested in solving the problem. You are like a cat playing with a mouse rather than killing it. Thats fine, if you have nothing else to do and "fixing" a simple carb for weeks/months at a time is a hobby for you, have at it. But it is in fact a simple fix and many people have told you how already.

For the carbon issue, use water injection. Its been done for a hundred years now (maybe more). Or take it apart and clean it. Its a simple job, dont make it more than what it is...

If your carb is running rich, on an engine that is notorious for being lean from the factory, then I will bet dimes to doughnuts that one of the previous owners was in that carb jacking around with things. A guy can do a lot of damage to a carb with torch tip cleaner, and you can end up trying to "fix" his mistakes by mixing your own gas for years. Thats cool if you need a hobby but not so much if you want to accomplish something. If you want it fixed, replace the jets, they are clearly opened up if you are running rich on a lean running engine. It will cost you about $4 and 45 minutes of your time. If that dont fix things (it will though), replace the carb. New carbs are available on Ebay for $20-50. Buy one with adjustable jets. Or dont and post for the next 3 year how you got duped into buying a new carb that is worthless and now you are mixing special gas just for you Kohler engine.

But like I said, I dont think you [b:c17ff2a830]want[/b:c17ff2a830] this fixed, I think you want to play around trying to find a longer, harder version of tried and true solutions. Because of that, the best we can do is wish you luck and encourage you to have fun because even if someone offeres to mail you a perfect fix, maybe a new carb, you wouldnt accept it (it has happened in other threads you started). So have fun and good luck.
 
Rich,
Please post a link where I can get jets for a 20 hp
kohler command, 2004. I'll buy them in a heart
beat.

I've never seen a carb like the one I have. The
jets appear to be fixed holes in the throat of
carb. One carb for both cylinders.
George
 
(quoted from post at 14:34:52 08/31/14) Rich,
Please post a link where I can get jets for a 20 hp
kohler command, 2004. I'll buy them in a heart
beat.

I've never seen a carb like the one I have. The
jets appear to be fixed holes in the throat of
carb. One carb for both cylinders.
George

Stop into your local Kohler dealer, they have drawers full of them in back where they work on the engines. Full carb rebuild kits too (but those will set you back a couple extra bucks).

Or.... if your local dealer is not very local for you, get them online. There are tons and tons of websites that sell parts and mail them to you.

Orrrrrr.............. just go to Ebay and buy a whole new carb. 20hp carbs are far from rare. Buy one, bolt it on and move on with life. Unless you enjoy this endless jousting at windmills and the lack of progress it provides.

Its really is that simple....
 
I did an advance search on ebay, came up with
nothing.

I have a local small engine parts place. I will
go there on tuesday to buy jets.

As for buying a new carb, I'll continue my
experiment, which so far has produced positive
results at a cost of about $.06/gallon.

Do you have any tech info on how to replace the
jets? Location of jets? Part #? I have experience
taking conventional carbs apart, never touched
this carb.
thanks
George
 
(quoted from post at 18:45:27 08/31/14) I did an advance search on ebay, came up with
nothing.

I have a local small engine parts place. I will
go there on tuesday to buy jets.

As for buying a new carb, I'll continue my
experiment, which so far has produced positive
results at a cost of about $.06/gallon.

Do you have any tech info on how to replace the
jets? Location of jets? Part #? I have experience
taking conventional carbs apart, never touched
this carb.
thanks
George

I dont believe you looked at Ebay, I did a google search on "ebay 20 hp carburetor kohler command" and in 3 clicks I was at a used carb for $20. Not ideal but very useful seeing as how you could take it apart and put it back to factory specs and then switch out your Bubba-ed carb to see how things are going. No joke though, 3 clicks and I found one... A couple clicks later and I was looking at 17hp all the way up to 27hp carbs. They are out there, not hard to find, we aint looking for a sasquatch, just a simple carb.

You dont know how to replace jets? You have never even had that carb apart? Well in that case, I withdraw my previous statement to stop at your local Kohler dealer to buy a jet and change it to; [i:e8cfaff2c1]Stop at your local Kohler dealer to make an appointment to fix your carb.[/i:e8cfaff2c1] If you need to be talked through a simple jet change and you havent even taken it apart yet, they you are in over your head. You cant see the jets from outside the carb so whatever you were looking at that "appear to be fixed holes in the throat of carb" are some other holes, not the jets.

Quit while you are ahead and make an appointment. Orrrr.... keep playing games because this really is a hobby for you and you dont really want it fixed.

Good luck!
 
You said I could buy jets for a 20 hp kohler
command on ebay for $4. Please post where you found
them. I'm not interested in a used carb.
 
(quoted from post at 20:50:20 08/31/14) You said I could buy jets for a 20 hp kohler
command on ebay for $4.

No, I did not, go back and read my responce again....


(quoted from post at 20:50:20 08/31/14) Please post where you found
them.



Stop into your local Kohler dealer, they have drawers full of them in back where they work on the engines. Full carb rebuild kits too (but those will set you back a couple extra bucks).

Or.... if your local dealer is not very local for you, get them online. There are tons and tons of websites that sell parts and mail them to you.

Orrrrrr.............. just go to Ebay and buy a whole new carb. 20hp carbs are far from rare. Buy one, bolt it on and move on with life. Unless you enjoy this endless jousting at windmills and the lack of progress it provides.

Its really is that simple....


(quoted from post at 20:50:20 08/31/14) I'm not interested in a used carb.

Then dont buy one. But it is a great way to fix your machine that you dont want fixed. Or do like I did, click a few more times and look at the new carbs, find one that fits and put it on. Or dont, because you just said in another post you didnt want to buy a new carb, you wanted to keep playing around with this new hobby, rather than fixing the problem. In any case, if you havent even opened up your carb, all the new jets in the world aint going to help you. Call and make an appointment so the dealer can fix your hobby for you...

Not only does it sound like you dont want this fixed and it really is only a hobby for you, it seems like you want a group hobby. Not everybody shares your love for refusing to simply fix a carb and draging it out into a months long affair. Anyway, like my grandma always said, "Its better than hanging out in the gin mill".

Have fun storming the castle!
 
I think I might storm the castle and see what
winter brings before I buy make carb changes.

The marvel carb on my Jubilee has a summer and
richer winter setting. Two full turns out on main
jet for winter mix.

So if I get another fixed jet carb, how will I
compensate for colder air?

I can very easily change ethanol ratio, not sure
about jetting. What size jets will I need. Will I
need to change jets for winter?

I'll keep the castle in place for now. I have no
windpower in castle either.

I really don't have a kohler dealer in town. I
have a small engine parts place that carries
mostly stens parts. Next time I'm there I'll
pick their brains.

I went to ebay. Never found a carb for CH20 that
looked like my older model. One did mention main
jet size, but what good does that do if I don't
know what size I need.

It would be very helpful if you have tech info on
main jet sizes and I'll buy them from you. But
going to ebay and buying a new carb without
knowing what's inside is like storming a castle.

I used to change main jets in my old holly carbs.
If I remember the main jet size really only
determines the max fuel the carb gets when you
are running wide open. I don't run my engine more
than half speed.

So am I trying to tip over windmills by changing
a fixed main jet?

I Think I would look cool wearing a set of armor
while operating my backhoe. Working on plans for
attaching the lance to the front bucket.

Thanks for all your help.
George
 
If you get another fixed jet carb, you compensate like all the millions and millions of other users that have zero problems.... you dont do anything. When properly set up it causes no problems at all. I shudder to think of all the carbs around this place and having to change between winter and summer settings and Im in a much harsher climate than you are, does that mean I should be going to 4 settings per year? Super cold winter, winter, summer and sweltering summer? Nah, I will just so it like everybody else, everything runs fine so I wont do anything untill its broke then I will fix it.

You make a good point, what good does it do it you are unable to take apart a carb, to even know or care when the next jet is? It really doesnt do any good. Thats why I said before, all the jets in the world aint going to do you any good if you cant do anything with them...

You are right, not running max rpm (or full load) means fuel is going through the idle circut as well and that jet will play a part in your running rich, further proof that any "experments" with mixing E85 is a waste of time and really just a hobby. Its non-repeatable. Just like you were shown how E85 can of of different ratios, thus non-repeatable, same goes for if you are running half speed, its non-repeatable because you cant set it exactally the same every time.

But I am glad you are enjoying your hobby and in looking back, you have been playing games for at least 5 years now. Thats a heck of a run but if you enjoy it, have at it....
 
(quoted from post at 19:15:52 08/30/14) Tell me how gas setting in a container with the lids on gets moisture.

Form the air in the can. The more air in the can, the more often you open it, the more moisture you'll get. It goes beyond that too. We have 10% ethanol here. I real cold weather it's not at all unusual for me to get 3- 7 gallon can of gas and find chunks of ice in them when I empty them. I'm talking chunks the size of a golf ball or larger. That comes from the tank mostly and all the alcohol in the world won't take care of it. The longer it sits, the more ice you'll get. And if you look in the can you'll see frost inside the can on the walls.

I don't know how much water is in typical gasoline, but my experience says there's quite a lot more than we think. Anyone in real cold country has seen icicles hanging off the inside of an exhaust pipe, the fog coming out of the pipe in a warm engine. Some is from intake air, true enough. Some is from fuel.
 

I'm with you Rich. He's looking for problems where they don't exist to justify a tinker hobby.
He has done it before with a strange reduced voltage starting system to operate equipment with an undersized generator. Instead of spending time and money better used on a larger generator .
 

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