Ethanol Fuels

Ethanol fuels were introduced in the U.S. around 2007. Ethanol or E10 is now the standard fuel at gas pumps and it means 10 percent alcohol. Ethanol is a by- product of corn turned into corn alcohol. Now,I am sure that I like corn on the cob and an alcoholic beverage as much as the next guy, but the detrimental effects that take place in a marine fuel system with this corn alcohol after a short period of storage are hard for anyone to swallow. 

Degraded fuel is the number one maintenance issue for small engine and power sports equipment owners today. This issue will only intensify in the next few years as ethanol content is increased at the pump.

Why Ethanol

Ethanol fuel was introduced as an alternative way to reduce our dependence on foreign oil and reduce emissions. Some boaters would argue that ethanol fuel reduces emissions because when their marine engines quit running due to the E10 fuel issues which usually occurs every spring on untreated fuel systems, it would naturally produce less emissions. While my research is not complete, there may be some truth to this theory!

Ethanol Effects

When ethanol fuel or E10 sits in a gas tank after a short period of time, usually 60 days or more, the ethanol and gasoline separate which leaves the ethanol at the bottom of the fuel tank since it is heavier. If there is any moisture available, usually through the vent, the ethanol absorbs it. That mass of water and ethanol finds its way to the fuel pick up and into the engine. Once this substance is introduced into the engines carburetors or fuel injectors, performance issues now begin. Performance symptoms include hard start, no start, poor running, backfire and stalling. Worst case scenario is complete engine failure since the ethanol which has no lubricating properties gets into the engine and seizes the motor on certain 2 stroke motors especially those that utilize premixed fuel and oil.

Ethanol also becomes a solvent and has been known to turn resin type fuel tanks into a mushy substance. It also deteriorates rubber in fuel pumps and lines causing serious damage to engines. Ethanol also removes varnish from the engine components which in turn clog fuel injectors and carburetor ports.

Filtering

The first step to prevention is water separation and filtering. It would make sense to install a high quality water/ fuel separator that is rated at 10 microns or less and can be drained easily so you can remove the water that settles at the bottom of the filter. Open the filter drain frequently to check for debris, rust particles and water contamination. I utilize Racor Filters but I believe Sierra and others manufacturers produce effective filtering products as well. 

Ethanol Fuel Stabilization

Fuel stabilizer products are critical to keeping the ethanol from reacting with oxygen. Put the stabilizer in your fuel tank when you re-fuel to allow the stabilizer to mix with the fuel. It is a good idea to do it year round unless you utilize all your fuel in a short period of time. Keep in mind that the storage period or downtime of 60 days and beyond is the main factor to the problems associated with ethanol.  There are numerous fuel stabilizer products on the market. Some good ones that I have utilized include STA-BIL, AMSOILQuickshot SE, STARBRITE Star*Tron fuel stabilizer.

Deposit Issues

Marine engines demonstrate their best efficiency and engine performance when they are new. As the engine ages, its performance suffers from gasoline fuel-generated deposits that form on the fuel injectors, intake valves and combustion chambers. Additives are necessary to control deposit formation. Today’s fuels, however, lack sufficient treatments of additives. Performance issues such as these are also signs of build up and deposits in the fuel system:

• Lost fuel economy
• Lost power and poor throttle response
• Poor drivability - surging, hesitation, stalling, rough idle
• Engine knocking (pinging) and rap
• Difficult starts

Deposit Clean-up

Port fuel injector deposits form after the engine has been shut down and there is no gasoline flowing through the injectors. During this “hot soak” period the injectors heat up and the gasoline remaining in the injectors degrades and forms deposits. This can happen very quickly with the use of poor quality gasoline and short trip driving. Because the clearances within the injectors are extremely tight and injectors must deliver precise amounts of “atomized” fuel, even small amounts of deposits can cause injectors to malfunction. Fuel flow is reduced and spray patterns are disrupted, decreasing engine efficiency, power and fuel economy. There are many products on the market that address this issue as well. Most fuel stabilizer products claim to do this as a secondary benefit. I believe additional additives or products provide better cleaning and performance in most cases. While there are many on the market,  AMSOIL Pi injector is the solution for me. It pays for itself in just the fuel mileage increase. In fact, many times throughout the year,    AMSOILprovides a money back guarantee if you feel that an improvement in performance or fuel mileage was not attained. How can you beat that!

E10 Preventative Measures Summary

• The key to eliminating the negative effects of ethanol is preventative measures. Install a high quality water/fuel filtering system capable of 10 microns or less and drain it frequently.
• Utilize a fuel stabilizer throughout the fishing season if your vessel will be stored for weeks at a time. This delays the ethanol fuel phase separation.
• Utilize a deposit control additive that will clean the fuel injectors, valves, combustion chamber and spark plugs to maintain or restore the engine to its original performance.
• If you have to store a boat fuel tank with ethanol fuel for any length of time, fill it as full as possible to limit the amount of air in the tank to reduce the absorption of moisture.

There are numerous products on the market that address some of the E10 issues. The complete list of E10 fuel issues needing to be addressed include: water in the fuel, dirty fuel, contamination, corrosion protection, ethanol fuel phase separation, carbon build up on injectors, valves, spark plugs and combustion chambers. AMSOILQuickshot SE won the prestigious SEMA award defined as the best innovative product, technical achievement, quality and marketability in 2011 for the Power Sports category that successfully solves these issues. For boat owners storing a lot of fuel, another solution may be to utilize a marine stabilizer such as STA-BIl or Star*Tron and then add AMSOILPi injectoradditive to thefuel system for total deposit control. This ensures injectors and combustion chamber remain clean while restoring performance. This is the procedure I do with my charter vessel, Fish On, equipped with twin 225hp Yamaha’s as I may be storing in excess of 80 gallons of fuel each winter.  I utilize AMSOILPi injector additive throughout the season and no stabilizers since I re-fuel every few days or sooner. I utilize AMSOILQuickshot SE to my 18 foot vessel with a Mercury 90hp 4 stroke since I have smaller quantity fuel tanks and that is where this product is the best option as both a fuel stabilizer and total combustion system cleaner. I have found these AMSOILproducts to improve overall engine performance. Always check first with your engine manufacturer before utilizing any fuel additive.

Good luck and safe boating!

Source:  AMSOIL

Captain John Sheriff has a BS degree in Industrial/Automotive Technology.

Former technical service representative for General Motors

President, Sheriff 5 Star Automotive Service Consulting        www.sheriff5star.com

Owner, Captain Sheriff’s Ocean State Synthetics                   www.oceanstatesynthetics.com        

Owner, Captain Sheriff’s Fishing Charters                             www.fishingchartersri.com