Fuel System - Onan MJA Series Service Manual

3.2 Fuel System
Standard MJA, MJB, and MJC engines use a gasoline, carbureted, fuel
system, to deliver a mixture of fuel and air to the combustion chamber.
The fuel system draws fuel from
a
tank delivers it through the filter
and fuel pump, and to the carburetor float chamber. Air passing
through the carburetor venturi section
draws
fuel from the float
chamber.
All fuel system components are described in the following paragraphs.
Select the components that apply to your plant.
3.2.1 FUELS
Use a "regular" grade of gasoline. They don't require premium gaso ­
lines. One of the most important things to consider is the content of
Tetra Ethyl Lead in the fuel. Premium fuels contain more lead than
regular, but the lead quantity also varies between brands of fuel. In
the constant speed operation to which generating plants are subject,
the build up of deposits in the combustion chambers is proportional to
the amount of lead in the gasoline. So, more lead means more deposits
and more frequent head removal for cleaning. On plants that require
frequent combustion chamber cleaning, the period between cleaning can
often be increased by changing fuel.
FUEL PUMP
FIG 3.2.A - GASOLINE FUEL SYSTEM