Air Cleaner Box Installation; Carburetion; General; Common Carburetor Problems - Generac Power Systems GN190H Service And Repair Manual

GASKET
CHOKE KNOB
AIR CLEANER BOX
Figure 2.3 — Removal of Air Cleaner Box,
Choke Style Carburetor

AIR CLEANER BOX INSTALLATION:

Install the air cleaner box to the engine and carburetor as
follows:
1. Using a new gasket, place the air cleaner box on the car-
buretor, line up the holes and install the two phillips head
screws (see Figure 2.2). If reinstalling the air cleaner box
with a choke style carburetor, line up the holes of the car-
buretor and air cleaner box with the holes on the intake
manifold before installing the phillips head screws (see
Figure 2.3). Refer to "Torque Specifications" on page 59
for proper torque.
2. Install the cap screw in the upper part of the air cleaner box.
Refer to Torque Specifications on page 59 for proper torque.
3. Reinstall the breather hose.
4. Reinstall the choke knob (units with choke type carburetor).
5. Install the filters and cover as stated in the preceding sections
on filter maintenance.

CARBURETION

GENERAL:

Proper engine performance depends on the carburetion
system. The use of clean, fresh fuel and a well maintained
air cleaner is extremely important to engine operation, as well
as engine reliability and power.

COMMON CARBURETOR PROBLEMS:

Most causes of carburetor problems are related to the use
of stale, gummy fuel and the ingestion of dirt. Prior to ser-
vicing any carburetor, be sure to check for evidence of these
conditions.
BREATHER HOSE
CAP SCREW
PAPER FILTER
FOAM
PRE-CLEANER
PHILLIPS HEAD SCREWS
SECTION 2: AIR CLEANERS AND CARBURETION
Gasoline that is left in the system for long periods can form
gum or varnish deposits that will adversely affect carburetor
operation.
NOTE: Use of a good fuel stabilizer will minimize the
formation of gum deposits during storage. Add the
stabilizer to the gasoline in the fuel tank or in the stor-
age container. Follow the mix ratio recommended on
the stabilizer container. After adding the stabilizer to
the engine fuel tank, run the engine for about ten (10)
minutes so it will enter the carburetor. A brand name
stabilizer can be purchased in most automotive repair
facilities or in lawn and garden centers.
Carefully inspect the carburetor choke and throttle shafts
for wear. Grasp each shaft and attempt to move it horizon-
tally and vertically. Maximum allowable end play for choke
and throttle shafts is 0.004 inch (0.1mm). Replace if exces-
sive play is evident.

ADJUSTABLE AND FIXED MAIN JET:

Some early production GN series engines were equipped
with a carburetor having an adjustable main jet. On later pro-
duction engines, a carburetor with fixed main jet is used.
Figure 2.4 — Typical Carburetor with Primer
Figure 2.5— Typical Carburetor with Choke
15