Specifications and requirements

comends that you use alcohol-free (see Gasohol) gasoline whenever possible.

Recommended gasoline:

Regular unleaded gasoline with a minimum Octane rating of 86 (Pump Octane Number) = (R+M)/2

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NOTICE

Do not use leaded gasoline. Leaded gasoline can seriously damage the en- gine.

Avoid getting water and contaminants in the fuel tank. Contaminated fuel can cause poor performance or engine damage. Use only fresh gasoline that has been stored in clean containers.

Gasohol

There are two types of gasohol: gasohol containing ethanol (E10) and that containing methanol. Ethanol can be used if the ethanol content does not exceed 10% and the fuel meets the minimum octane ratings. E85 is a fuel containing 85% ethanol and must not be used in your outboard motor. All ethanol blends containing more than 10% ethanol can cause fuel system damage or cause engine starting and running problems. Yamaha does not recommend gasohol containing methanol because it can cause fuel system damage or engine performance problems.

It is recommended that you install a water- separating marine fuel filter assembly (10 micron minimum) between your boat’s fuel tank and outboard motor when using etha- nol. Ethanol is known to allow moisture to be absorbed into boat fuel tanks and systems. Moisture in the fuel can cause corrosion of metallic fuel system components, starting and running complaints and require addition-

al fuel system maintenance.

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Ring Free Fuel Additive

Gasoline is a precise blend of many different substances, each chosen to give certain characteristics. Gasoline blends have been changing in recent years in response to concerns about pollution and resulting emissions regulations. One of the most obvious changes has been the elimination of lead from most fuels.

As gasoline has changed, the amount of additives such as aromatics and oxygenates has increased. These additives are important for the engines in passenger cars, but they can have detrimental effects in marine engines, because of increased deposits in the combustion chamber. When enough deposits collect, piston rings begin sticking. Performance drops and engine wear increases dramatically.

While many additives available may reduce deposits, Yamaha recommends the use of Ring Free Fuel Additive, available from your Yamaha dealer. Ring Free Fuel Additive has repeatedly proven its ability to clean combustion deposits from inside the engine, notably the critical piston-ring-land area, and fuel system components. Follow product labeling for use instructions.

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Muddy or acidic water

Yamaha strongly recommends that you have your dealer install the optional chromium- plated water pump kit if you use the outboard motor in muddy or acidic water conditions. However, depending on the model it might not be required.

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Anti-fouling paint

A clean hull improves boat performance. The boat bottom should be kept as clean of ma-

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