Generac Power Systems 941-2 Service Manual page 57

GENERAL
Recreational vehicle generators equipped with a
gasoline fuel system are usually installed so that they
share the fuel supply tank with the vehicle engine.
When this is done, the generator Installer must never
tee off the vehicle fuel supply line to deliver fuel to the
generator.
When the generator fuel supply line is teed off the
vehicle's fuel supply line, the more powerful vehicle
engine's fuel pump will starve the generator when
both are running. In addition, when the vehicle engine
is not running the generator fuel pump will draw all of
the gasoline from the vehicle engine line or even from
the vehicle engine carburetor. This will result in hard
starting of the vehicle engine.
One method of sharing the same fuel supply tank is to
Install a special fitting at the tank outlet so that two
fuel dip tubes can be fitted In the tank (Figure 1).
Another method Is to install a new outlet In the tank. If
the tank has an unused outlet, It can be used.
A second fuel dip tube can be installed in the original
tank outlet if the tank outlet is large enough to accom-
modate two dip tubes. The required fittings can be
made at a machine shop. To install a second fuel out-
let on the tank means removing the tank to braze or
weld a new fitting into place.
DANGER! ATTEMPTING TO WELD OR BRAZE
!
ON A FUEL TANK, EMPTY OR NOT, IS
EXTREMELY DANGEROUS. FUEL VAPORS IN
THE TANK WILL RESULT IN AN EXPLOSION.
The generator's fuel dip tube in the tank should be
shorter than the vehicle engine's dip tube. This will
prevent the generator from consuming the entire fuel
supply.
DANGER! THE FUEL SYSTEM DESIGNED
!
AND INSTALLED BY THE GENERATOR MAN-
UFACTURER IS IN STRICT COMPLIANCE
WITH STANDARDS ESTABLISHED BY THE
RECREATIONAL VEHICLE INDUSTRY ASSO-
CIATION (RVIA). NOTHING MUST BE DONE
DURING MAINTENANCE THAT WILL RENDER
THE SYSTEM IN NON-COMPLIANCE WITH
THOSE STANDARDS.
INTRODUCTION TO FUEL SYSTEM
DANGER! THERE MUST BE NO LEAKAGE OF
!
GASOLINE OR GASOLINE VAPORS INTO THE
VEHICLE. THE GENERATOR COMPARTMENT
MUST BE VAPOR-TIGHT TO PREVENT
ENTRY OF FUEL VAPORS OR FUMES INTO
THE VEHICLE. THE GENERATOR'S VENTILA-
TION SYSTEM MUST PROVIDE A FLOW OF
AIR THAT WILL EXPEL ANY FUEL VAPOR
ACCUMULATIONS.
RECOMMENDED FUEL
Use a high quality UNLEADED gasoline. Leaded
REGULAR grade gasoline is an acceptable substi-
tute.
Do NOT use any fuel containing alcohol, such as
"gasohol". If gasoline containing alcohol is used, it
must not contain more than 10% ethanol and it must
be removed from the generator fuel system during
storage. do NOT use fuel containing methanol. If any
fuel containing alcohol Is used, the system must be
inspected more frequently for leakage and other
abnormalities.
Figure 1. Sharing a Fuel Supply Tank
EVAPORATION CONTROL SYSTEMS
Federal and state laws have imposed strict evapora-
tive controls on gasoline fuel systems. The recreation-
al vehicle industry has complied with such strict regu-
lations by using specially designed fuel tanks, tank
filler tubes and gas caps. Special canisters are often
used to collect the gasoline vapors rather than let
them escape into the atmosphere.
Such systems are designed to operate within very
critical pressure ranges. For that reason, the vehicle
manufacturer's fuel supply system design must not be
Section 3.1
Page 3.1-1