INTRODUCTION TO WHEELED VEHICLE
FUEL AND EXHAUST SYSTEMS
It is the job of the fuel system to send the correct fuel-air mixture to the engine at all times. The
contents of the mixture and the amount of the mixture must be variable to meet the ever-changing needs of
the engine. Through the years, it has taken a lot of research and experiments to develop the present-day fuel
system. This system must be serviced and maintained properly or it will not work as it should.
The combustion (burning) of the fuel with the air in an engine includes several chemical changes. For
example, for each gallon of gasoline that is burned, about one gallon of water is produced in the form of
steam. Another thing that is formed is carbon monoxide, a colorless, odorless, deadly, poisonous gas.
The exhaust stroke rids the engine of most of these combustion products, and the exhaust system takes
the exhaust fumes away from the engine, cuts down the noise, and gets rid of the gases so that none of the
carbon monoxide reaches the people in the vehicle. For safety of personnel, proper maintenance of the
exhaust system is a must.
The purpose of this subcourse is to give you the knowledge to develop the skills to service and maintain
fuel and exhaust systems.