Yamaha BIG BEAR 400 Owner's Manual - Fuel Cock

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CAUTION:

ECB00070

Use only unleaded gasoline. The use of leaded

gasoline will cause severe damage to internal

engine parts, such as the valves and piston

rings, as well as to the exhaust system.

Your Yamaha engine has been designed to use

regular unleaded gasoline with a pump octane

number [(R+M)/2] of 86 or higher, or a research oc-

tane number of 91 or higher. If knocking or pinging

occurs, use a different brand of gasoline or premi-

um unleaded fuel. Unleaded fuel will give you long-

er spark plug life and reduced maintenance cost.

Gasohol

There are two types of gasohol: gasohol contain-

ing ethanol and that containing methanol. Gasohol

containing ethanol can be used if the ethanol con-

tent does not exceed 10%. Gasohol containing

methanol is not recommended by Yamaha be-

cause it can cause damage to the fuel system or

ATV performance problems.

WARNING

EWB00270

EBU18820

Fuel cock 

The fuel cock supplies fuel from the tank to the car-

buretor while also filtering it.

The fuel cock lever positions are explained as fol-

lows and shown in the illustrations.

POTENTIAL HAZARD

Improper care when refueling.

WHAT CAN HAPPEN

Fuel can spill, which can cause a fire and se-

vere injury.

Fuel expands when it heats up. If the fuel

tank is overfilled, fuel could spill out due to

heat from the engine or the sun.

HOW TO AVOID THE HAZARD

Do not overfill the fuel tank. Be careful not to

spill fuel, especially on the engine or ex-

haust pipe. Wipe up any spilled fuel immedi-

ately. Be sure the fuel tank cap is closed

securely.

Do not refuel right after the engine has been

running and is still very hot.

U4S110E0.book  Page 17  Friday, August 4, 2006  4:03 PM