Why won't my small power equipment start?

Separation of the water and the fuel.

"But we just had our carburetor cleaned last year? Why do we need to do it again this year?"

This is one of the most common questions we hear in our repair shop. And it's one of the biggest frustrations from our customers. We recognize this frustration and hope to help others understand the problem better. In this post we hope to shed the light on the issue. The problem is caused by the ethanol that is found in most fuels today, which causes something called Phase Separation. Whether you use gasoline as a fleet operator or for your family car, classic car, boat, personal water-craft, motorcycle, snowmobile, ATV, RV, lawnmower, weed-whacker, generator, or any of the thousands of other types of equipment that use gasoline engines; you are being affected by Ethanol in your fuel.

Separation of the water and the fuel.

Phase Separation describes what happens to gasoline containing Ethanol when water is present. When gasoline containing even small amounts of Ethanol comes in contact with water, either liquid or in the form of humidity; the Ethanol and water will Phase Separate, actually coming out of solution and forming two or three distinct layers in the tank. Phase Separation is also temperature dependent. For example, E-10 can hold approximately .05% water at 60°F. To better understand the amount of water that we are talking about, picture 1 gallon of E-10 at 60°F. This gallon will hold approximately 3.8 teaspoons of water. However if the temperature drops to 20°F it can only hold about 2.8 teaspoons of water. Phase Separation can happen in an underground or an above ground storage tank, a vehicle tank, a boat tank, in any type of equipment tank, and even in the gas can in your garage. When this happens, you can have serious and even catastrophic engine problems, without warning. When this Phase Separation occurs you will have an upper layer of gasoline with a milky layer of Ethanol and Water below it, and then in many cases a third layer of just water at the bottom. If this happens and you try to start the engine you can have one or more of the following problems. If your fuel tank pick-up tube is in the water layer, most likely the engine will fail to start. If the engine is running and suddenly draws water you can have damage from thermal shock or hydro-lock. If the pick-up tube draws the Ethanol-Water mixture or just Ethanol you can have problems where the engine will operate in an extreme lean condition, which can cause significant damage or even catastrophic failure. If the pick-up tube draws the gasoline, it will operate very poorly due to lower octane that is the result of no longer having Ethanol in the fuel. Gasoline containing Ethanol provides further challenges and dangers for marine operators (Boaters) and other users of seasonal equipment such as motorcycles, personal water-craft, snowmobiles, ATV's, RV's, yard maintenance, generators, and other equipment. Ethanol is a strong, aggressive solvent and will cause problems with rubber hoses, o-rings, seals, and gaskets. These problems are worse during extended storage when significant deterioration will take place. Hoses will delaminate, o-rings will soften and break down, and fuel system components made from certain types of plastics will either soften or become hard and brittle, eventually failing. Fuel system components made from brass, copper, aluminum will oxidize to the point of failure. Two-Cycle engines have a special problem with Ethanol blended fuels. Two-Cycle engines function because the oil added to the fuel bonds to the engines metal surfaces and provides barrier lubrication to all the parts requiring lubrication. When Ethanol is added to the gasoline, it displaces the oil and forms a primary bond with the metal surfaces. This bond provides virtually no lubrication and can result in significantly increased wear and even catastrophic failure in a very short amount of time. Ethanol has less energy (as measured in Btu's - British Thermal Units) per gallon than does regular unleaded gasoline. This means that the more Ethanol found in fuel the worse your fuel economy will be. You use more gallons of fuel containing Ethanol to go fewer miles. This poor fuel economy is made worse by other EPA and State requirements for fuels to change seasonally. Until very recently we have used what is known as "Conventional" gasoline (CVG) in the winter and "Reformulated" gasoline (RFG) in the summer. The theory is that the lower volatility of RFG will reduce the formation of green house gases. However RFG has lower Btu's per gallon. RFG together with Ethanol results in significant mileage penalty. My own vehicle drops about 2 miles per gallon or about 9% when using RFG with Ethanol. For many years the refining industry used a chemical MTBE to meet the oxygenate requirements set forth by the EPA. Generally refiners used 15% MTBE and 85% gasoline. However MTBE has now been virtually eliminated in the US due to its carcinogenic compounds and the huge potential problems caused by its pollution of as much as 75% of the ground water in the US and Canada. This has left Ethanol as the primary additive to meet Federal and State oxygenate mandates. Further the federal government currently subsidizes Ethanol with a $.51 per gallon tax credit that goes to refiners or blenders. With E-10 this provides those refiners and or blenders with a $.51 per gallon subsidy on every gallon of gasoline that they sell.

A new carburetor and one showing the gum and varnish built up because of the ethanol.

One more concern with Ethanol and RFG or Ethanol and CVG is that Ethanol when mixed with water; they readily form Gums in the fuel system much quicker that gasoline without Ethanol. These Gums coat fuel system components including filters, carburetors, injectors, throttle plates; and will then form varnish and carbon deposits in the intake, on valves, and in the combustion chamber. These deposits can coat sensors and plug catalytic converters. The good news is that we now have products available to prevent and control Phase Separation and that we can dramatically reduce or eliminate most of the problems caused by the Ethanol in the gasoline.

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For seasonal vehicles and equipment, e.g. boats, personal water-craft, motorcycles, classic cars, ATV's, RV's, lawn and garden equipment, gasoline powered generators, and so on, we recommend that you try to use conventional gasoline without Ethanol whenever possible and particularly prior to storage. In ALL Two-Cycle gasoline engines where there is any possibility that you are using gasoline containing Ethanol we strongly suggest using a full synthetic two-cycle oil in the gas.