I'm running E85/Ethanol(when should I expect something to go wrong)

[Mozenrath]

Contrary to popular view of ethanol, I got very adventurous. I want to see if these engines can actually run E85. The original purpose for building my bike was for short-term commuting, and seeing as how I ended up not needing it for that purpose, the bike is used for 100% fun. Still, half the fun I have in life is experimenting, and my bike hasn't been spared!

From what I read, there are 3 things that have to work for a 2-smoker to run ethanol.

1. Ester-based synthetic oil(since apparently normal synthetic won't dissolve)
2. Seals that will hold up to the ethanol.
3. Larger carb jet(haven't done this yet).

So I actually found a cycle shop nearby that sells bottles of pure ester-based 2-stroke oil. It was referred to as racing oil, but said it could be used in any air cooled 2-stroke engine.

Mixed it together with some E85 in what seems to be the only E85 station in LA. I went with a 16:1 mix, because while I understand I'm risking blowing up my engine, I might as well go a little bit over on the oil to be on the safe side. I'm also thinking the ethanol will wipe away a lot of the present non-synthetic oil in the engine so there should be plenty to replace it.

The first time I ran the mix, I left the settings on the carb the way they were to see if modifying anything would even be necessary. The engine did not run.

So I opened up the carb, and it turns out that the blue seal/gasket had melted from the ethanol. I had already tested my purchased gasket material with the ethanol and it worked fine so I wasn't too worried about replacing the carb bowl seal, but what I was afraid of was the gasket that's sandwiched between the two parts of the engine. However, it seems to have withstood the ethanol. My damn stock petcock started leaking again and some of the ethanol puddled up on that gasket. Nothing seemed to happen, and I even left it there for quite a while and I inspected it afterward, so I think I'm okay there.

After adjusting the carb needle to richen the mix(4th notch), the engine started. Although I think the reason it didn't start at first was that I may have forgotten to turn the petcock to the on position. The engine started and got me a little down the road but couldn't quite get me up the hill again without bogging.

So I adjusted the needle to the 3rd notch and tried again. With the choke just a little bit up, I actually got the engine running really well! Well enough that I was able to make my daily 3.5 mile ride without any noticeable difference in speed or power! Of course that may be a placebo due to thinking my engine would fail much sooner, but who the heck knows! I read that ethanol would decrease the power significantly, but even if it did it still was able to pull me up a really steep hill!

The only difference I notice in the running is that the throttle lags for just a half-second. Like when I'm coming to a stop, I'll release the throttle and pull in the clutch, and the engine will still rev higher for a brief moment and come down to the idle speed. Vise-versa happens when starting from a stop. This doesn't really effect the ride much though, but it's just something I noticed that happens differently with the ethanol fuel. I also liked coming home and not smelling like gas/exhaust!

So far I have only ridden my bike on the E85 for 3.5 miles. My question is if I were to experience engine failure due to ethanol, when should I start experiencing it? Like if I didn't use the correct oil(though I did), would my engine have seized by now?

 

[camlifter]

i ran e-85 mixed half and half with 87 oct gas. used normal 2cyl oil. ran ok, did about 2 tanks of fuel that way. with straight e85 your probably running lean and pushing your luck.

 

[Mozenrath]

If I were running lean, wouldn't that mean it'd be idling like crazy?

Anybody know how to drill out the jet?

 

[dmb]

its [the jet] allready got the pilot hole go twice as big and the motor should run cold to the touch. the 15% gas is their to stop people from drinkin it!

 

[Mozenrath]

I heard that the hole is big, but I didn't think it was that big! Still, I think I'm going to drill it out with a #64 drill bit, if I can get one today. Apparently you need 30% more alcohol to get the same amount of power as you would have from gasoline, so if the engine runs fine on gas with the jet the way it is now, I probably need to make the jet even larger to get the same amount of power. I don't need much more, but there is a slight drop in power when I use the ethanol.

 

[GearNut]

Check the carburetor and fuel valve in about 6 months.
E85 attacks aluminum and corrodes brass. It will also attack the white plastic that the float is made out of.
It will also attack most gasoline resistant rubber seals and gaskets as you all ready have found. Be sure to check the black Viton rubber tip on the float needle. I have seen them swell up to twice original size and the float mechanism cannot maintain the proper fuel level in the float bowl. That was with E10 and a cheap chinese carburetor rebuild kit.
E85 is worse.......

 

[Mozenrath]

Which fuel valve? The petcock or the the valve inside the carb? I just chucked the stock petcock. I have never noticed a black vitron tip on the float needle, but maybe I never looked close enough. When I drill out the jet I'll probably take a better look then. I'm assuming the float needle is the same thing as the slide needle, or is this something different?

EDIT: I am guessing this is what you're talking about?

I haven't looked at the actual one in my carb, but this one does not appear to have any special tip. I could be wrong, but it appears to be bare metal. If mine does have a vitrol tip, is there any way to modify it so there are no issues with the ethanol?

I soaked the float for a while in the ethanol and it didn't seem to make a difference. Other things I soaked in it like a tupper ware container got screwed up and a plastic cup I had melted pretty quickly, so I guess that's a sign that either the float won't corrode or it will just corrode over a long time.

Is it more likely that the seals will get wrecked over a longer period of time? The seal on the float bowl was the only one that melted pretty instantly. I took off the clutch cover gasket and soaked it for several minutes in the ethanol and nothing happened.

The only seals that haven't been replaced is the main engine gasket and the gasket between the engine and the cylinder. The intake, exhaust, float bowl, clutch cover, and magneto cover gaskets have all been replaced with better material that seems to withstand the ethanol.

 

[Al.Fisherman]

I believe what was mentioned is the tip of the float needle (top of your picture). The float needle fits into a seat and the tip is made of many different materials such as rubber. No telling what the Chinese use. But one thing, it's the cheapest available, I'm sure.

 

[GearNut]

Not every needle made will have the rubber tip. If yours is solid metal then that's one less thing to worry about. Ethanol damage occurs over time. That's about 6 months of fluid contact to see the beginnings of the corrosion.

Do a web search on ethanol damage, specifically snow blowers, lawn mowers, general yard equipment if you want more examples.

 

[James912]

Add a good brand carb cleaner into your gas tank, that'll help keep your carb clean and the ethanol at bay.

 

[Mozenrath]

I opened up the carb and the needle is bare metal(and surprisingly pointy!).

I bought a #60 drill bit, which was the smallest one I could find, and I drilled out the main jet by hand. I wanted to go with a #64 but no store seemed to sell any less than 60, but I'm impatient by nature so I went with the 60. If it ends up being too rich, I'll just order a #64 bit and solder/redrill. I didn't get a chance to properly test the engine today because my gas tank keeps leaking. This happened before the ethanol but it's been dripping enough that fuel drips on the engine, and I just can't put up with that anymore. What's worse is that I have to drain the fuel out of the tank after each ride, which is a huge pain! So I've epoxied the tank and next time I find a cheap mini keg, I'll make a tank out of that.

Anyway, I'll be testing again tomorrow. I'm going to be looking into fuel treatments, although I've always been skeptical that such products actually work.

EDIT: So far, all the confirmed problems caused by ethanol on the internet seem to be caused by contact with rubber/plastic materials and plastic coatings. Also seems like there's more of a problem with small engines that are more than 10 years old. But I'll keep looking. So far I'm not too worried since there really aren't that many plastic/rubber products on my bike, outside of the gaskets, float, and fuel line(which I replaced with line that turns out to actually be ethanol resistant, according to the guy at the auto store). They say that the engine will run hotter, but mine didn't seem to run much hotter.

 

[glennbo]

im curious on how long the plastic float will last keep us posted
glenn

 

[Dan]

Purty fascinating Moz. Please keep us posted.


I can't remember how many engines I have destroyed experimenting. Nothing like first hand learn'n. Thanks for sharing. (and sacrificing if that comes to pass, lol)

This is cool! Grow your own gas! HowStuffWorks "Can I make my own ethanol?"
Or
make your own ethonal - Google Search

This would be a cool project! I might try it for 4 smokes.

Imagine answering the question; "Not only did I build it, I grew my own gas too" snicker, snork, snork

Sincerely,
Dan "just can't stay on topic" Keav

 

[Mozenrath]

Okay, I've been fiddling around with the jet size and I think #60 drill bit was too big. I soldered and drilled a #67 hole, and I can get the bike started, but in less than 10 seconds it starts bogging and I have to stop. Then when I start again after about 10 seconds it starts fine and I take off but then it suddenly slows down again.

Would I be right in guessing that I need a better spark plug? Right now I'm using an NGK B6HS.

 

[GearNut]

it could be the spark plug, it could be a fuel delivery problem between the fuel tank and fuel jet.

 

[Mozenrath]

I replaced the sparkplug with an autolite one with gold and platinum with a tiny tapered tip. Worked just fine when I tried it, but I have the same problem running it with the E85. It starts out and everything, but with any kind of hill it bogs and the engine stops working. I wish I could have stuck with the stock jet and just ran it at half-choke. Worked just fine then and I was able to make my daily route.

I don't believe there's a problem with the fuel delivery. I chucked out the stock petcock and replaced it with a brass barbed spout that came from OSH and fit perfectly into the stock tank, and inbetween it and the tank I got a plastic petcock that actually has a bigger throughput than that stock. I was actually shocked when I took apart the stock petcock; the holes on the inside are smaller than the spout! I also no longer have the in-tank screen, but I still have an inline fuel filter. When I pull out the fuel line, fuel rushes out of it nicely.

Then again, is there a chance that too much fuel is rushing into the carb? When I first got the bike running on E85, I had taken the switch off the stock petcock and covered it with Quik Steel and used the new plastic petcock with it. Maybe I'll try somehow restricting the fuel flow and see what happens. When I have more money, I'll probably switch to a ball valve at some point. The plastic one seems fine for now.

Right now it's too late to be testing my loud motor outside, but I'm going to take apart my carb and make sure I didn't fudge anything up the last time I opened it. If I can't figure out what's wrong by tomorrow, I'll post a video. I don't see why my engine should run worse on E85 with just a 13% larger jet. I was under the impression that the jet had to be 30% larger, but so far that's seemingly untrue.

 

[Mozenrath]

I opened up the carb, and then I noticed that I can't see through the fuel inlet. I poked into it with a drill bit and there seems to be something rubbery in the way. Is something like that supposed to be there? I think it might be dirt, but I don't want to mess with it if it's something that's supposed to be there.

Here's what I'm talking about:

There's something obstructing it, and I'm guessing it's either two things: Dirt(if I put the filter on the wrong way) that's obstructing it, or a piece of rubber that's supposed to be there.

EDIT: It was crud. I think, anyway. I hope it was just crud. I pushed a little harder with the drill bit and out came a bunch of little chunks of rubber black plastic that I think came from my gas can when it got caught in the fuel tank, and at one point I may have put on the fuel filter the wrong way. I'm surprised any fuel got through.

 

[dmb]

a little bubble gum stops leaks [old desert racer trick] where does that fine chineezze tank leak?

 

[Mozenrath]

It leaks around the base of two of the studs, but actually there was a small crack that I didn't find the first time and I think that's where most of the leaking came from. I patched it with some Devcon epoxy, and now the leak is gone for good.

The bike runs great on the ethanol! I read that you need a better spark plug to run with ethanol in a 2 stroke, but my NGK B6HS works just fine. Though actually right now I switched it with a platinum and gold Briggs and Stratton plug because it's not only a better plug but since it's clean I can better gage whether or not I'm running rich or lean.