Service Manual
Carburetor
Pressure.
Testing
1.
Turn the carburetor upside down.
2.
Connect a pressure tester to the inlet fitting on the
carburetor. See Figure
17.
Figure
17
3.
Pump the pressure to the inlet needle "pop
off
pres-
sure,
5
psi
(.3
kglcm
2).
4.
The inlet needle should
seal.
If the pressure leaks
down to zero, the inlet needle is not seating indicating
that carburetor service is required.
Carburetor Disassembly
1.
Remove the bowl nut, bowl and gasket.
2.
Use a
9/16"
wrench to remove the main jet and float
stop disc. See Figure
18.
Figure
18
3.
Remove the float hinge pin, float and inlet needle.
4.
Remove the idle mixture screw and spring and the idle
stop screw and spring. See Figure
19.
GTS
150
21
IDLE
STOP
SCREW
IDLE
MIXTURE
SCREW
.-
Figure
19
5.
Thethrottle plate is retained with one screw. When the
plate is removed the throttle shaft may be withdrawn
from the body of the carburetor.
6.
The choke plate is retained in a slot
in
the choke shaft
with
an
interference
fit.
The plate may be removed by
pulling
it
out
of the slot with a pair
of
pliers. The choke
shaft may then be removed from the body of the
carburetor.
7.
If the carburetor vent passage is open
it
is not neces-
sary to remove the welch plug that covers the vent
opening
in
the bowl
of
the carburetor. This is a vent
area that does not have a filter screen or other
cleanable device.
8.
Remove the pilot circuit welch plug from the side of the
carburetor. Pierce the plug with a small chisel or
pointed device and pry the plug out of the body of the
carburetor.
9.
The viton, fuel inlet seat may be removed by pulling the
seat out
of
the body
of
the carburetor with a number
5
crochet hook.
Carburetor Cleaning and
Service
I.
CAUTION:
Wear gloves that are suitable for
use with chemicals and wear eye protection when
working with carburetor cleaning materials. Work only
in
well ventilated areas free from sparks or flames.
Make sure you follow all manufacturers recommen-
dations on the use of their cleaning products.
2.
The carburetor
body
and components may be soaked
in carburetor cleaner, however; after the soak, each
passage and component in the carburetor should be
washed with a pressurized carburetor cleaning agent.
Soak tanks may not
be
clean and the pressurized
cleaner will remove any residue.
3.
Direct the pressurized cleaner through all openings
and passages
in
the opposite direction of normal fuel
or air flow.
Carburetor