View Single Post
Old 09-18-2011, 01:32 AM
Mozenrath Mozenrath is offline
Motorized Bicycle Elite Member
Join Date: Jan 2011
Location: California
Posts: 340
Red face I'm running E85/Ethanol(when should I expect something to go wrong)

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?
Reply With Quote