Note: I have a tendency to wall of text some of these. Please scroll to the end of the post if you would like a brief summary.
As most of you have probably noticed, over the last decade or so, nearly every gas station in the US now has stickers that say 10% ethanol has been added to unleaded fuel. For most people, they can simply ignore this. The reason for this addition was to “reduce cost of fuel”, but really it’s a whole government racket between farmers and it technically zeros out due to various reasons. I won’t get too into that, but there is a plan to eventually move to 15% ethanol content which could be very bad for even slightly older cars that were made before 2001.
A lot of people are unaware of what any of this means, and how it is impacting things like lawn mowers, generators, older vehicles, and our beloved Honda Twins. Luckily for all of you I have researched this fuel for a couple papers in school, and have found what has been a reliable solution to the problems ethanol can cause.
Getting into why ethanol is such a big bad thing for us requires some basic scientific knowledge. HOORAY SCIENCE!
Ethanol is an alcohol, typically made from corn or other sustainable sugar sources, that increases detonation of fuel in your engine with the added benefit of burning colder than gasoline. Adding a small amount to fuel doesn’t really make that much of a difference overall, but due to its properties this alcohol can be detrimental to old rubber, steel tanks, and carburetors.
Rubber fuel line and o-rings are typically Nitrile when dealing with older vehicles. These work great for petroleum based oil and fuel, but are not resistant to ethanol. Synthetic Rubbers like Nitrile require oil. Dry rot is a result of the oils evaporating out of the rubber and will result in hard, brittle lines and seals that will leak and cause all types of vacuum issues. There are also some vehicles that use rubber or plastic float bodies that can fail due to ethanol. Since ethanol is an alcohol, it can permeate the Nitrile and then evaporate, taking the oils with it and speeding up the dry rot of Nitrile. It also dry rots seals that would typically not be an issue due to heat, light, or air exposure. This dry rot effect is why my ‘73 240z left me stranded on the side of the highway in El Paso on my birthday. It ate through the membrane in the mechanical fuel pump!
The fix for this is to replace any fuel line with neoprene, tygon, or nylon lines. Neoprene is the more common rubber line found on most fuel injected cars. Tygon is a clear tubing used on brake reservoirs, new small engine fuel systems and even aircraft hydraulics, and most large manufacturers are now using nylon fuel lines. All three of these have better chemical resistance than Nitrile, with Neoprene fuel line being the cheapest, easiest to work with, and easiest to find.
For gaskets and O-rings many newer offerings are butyl or neoprene and will stand up to ethanol okay. They are also cheap enough that replacing more often isn’t a problem. You can go crazy and get coated o-rings that cost a fortune. Or, if you’re willing to spend in the mid-range, get a kit with various sized Viton o-rings. These will stand up very well against ethanol, and are even recommended for E85 applications.
So that solves one problem that ethanol presents. What about the others?
Ethanol is an alcohol. Alcohols are made by the fermentation of sugars. Ethanol that isn’t perfectly pure can leave behind those sugars or other contaminants when it evaporates causing a gooey mess inside carbs, tanks, and filters.
Why does it evaporate or collect contaminants though? Since Ethanol is a chemical compound made by fermentation, it’s molecules are “dry” meaning that it will attach to any water or moisture. This causes it to then separate from the gasoline since oil and water don’t mix. Once it separates Ethanol will evaporate faster than the gasoline. Leaving behind any sugars or contaminants turning fuel in your carbs into a gummy mess. Yuck!
This is also a problem for old steel tanks. Ethanol has a slightly higher density than gasoline, especially when it soaks up water. So once it separates, the ethanol will sink to the bottom of your tank, taking the water with it. This will result in rust on the bottom of you tank. It can also mean that even by sitting overnight or a couple days the fuel in your float bowls will separate making it harder to get your bike started. If left over the winter, this can cause corrosion of aluminum parts leaving a white chalky crust on everything in your carbs.
It is practically unavoidable with a car, bike, or small engine, because any moisture in the air will be absorbed by the ethanol. There is also no real way to know that the fuel you are getting from any gas station doesn’t already have some water in it. This is compacted by heat and condensation. So what do you do about that?
Well, you could get lucky and happen to live somewhere that ethanol free gasoline is available. I am in a more rural area, with a lot of farmers that prefer to use it. (Funny that the people that grow a ton of corn to make ethanol, prefer not to have it in their gasoline.) That means there are a couple stations that offer ethanol-free. However, it is usually more expensive, and I have to only fill up at those locations.
Instead I found this.
http://www.starbrite.com/item/star-t...oline-additive
This fuel additive is specially formulated to combat the bad behavior of ethanol, and it is honestly the only one that has worked well for me. I am in no way affiliated with the company, I just discovered it ten years ago and now swear by it for any ethanol related issues. Sta-Bil does make a better product for storage, but doesn’t improve overall performance. The reason an enzyme treatment is important is because it will stabilize the ethanol in the mix. Preventing separation, and converting any impurities. I have used it in my ‘73 240z, ‘77 VW Bug, ‘69 VW Bug, 2005 CBR, lawn mowers, weed whackers, generators, and anything else with a carb. This spring I started my mower up after it had sat with a full tank of E10 unleaded since Nov. with zero issues.
It is likely that the E15 move will happen, and when it does it will create a lot of problems for everyone. Hope this info was helpful or interesting!
***I don’t feel like reading all of that section***
Ethanol is an Alcohol additive to fuel, usually corn based, that increases the octane rating. However, most older vehicles are not built to withstand the harshness of this chemical and it can accelerate dry rot of fuel lines and rubber gaskets/seals. It also separates from gasoline while sitting and is hygroscopic. Meaning it will absorb water and cause rust or corrosion to tanks and carbs. It can also gum up when it starts to evaporate because it has sugars in it.
I use a product called Star Tron to stabilize fuel that contains ethanol and have had great results over the past ten years.
Sent from my iPhone using Tapatalk
Reply With Quote
Originally Posted by 1969 CL350
hey, that's why we're here.
