P 11/ 15
See
Figs. 28 and 29
for the positions of Needle-idle (L) and Needle-high speed (H).
Carburetor has two different specifications (Walbro-made and ZAMA-made).
After tightening each Needle to the full, loosen them as listed below.
Fig. 28
Fig. 29
R
epair
Needle adjustment
Pressure test
General check
[2] DISASSEMBLY/ ASSEMBLY
[2]-10. Air filter, Carburetor, Intermediate flange (cont.)
Fig. 30
Fig. 31
(S)
L
H
(1) Connect 1R127 to Carburetor. (
Fig. 29
)
(2) Push up the air pressure until the pressure gauge indicates
0.05 Mpa.
(3) The carburetor is in order if the air pressure can be kept for
10 seconds.
Note
: If the air pressure drops, check the following conditions.
• Valve-inlet needle: if necessary, Spring, Lever-metering,
Pin-metering lever, and Plug-welch have to be replaced
together. (
Fig. 30
)
• Dirt/ deposits on the top of Valve-inlet needle: clean it.
• Gasket pump and Diaphragm-pump: replace them
with the new ones.
• Inlet screen should be clean.
• Pulse hole should be clean.
Check around Valve-inlet needle and Lever-metering
Check Diaphragm-pump
Check Diaphragm assembly-metering
Refer to
Figs. 30
and
31
.
Check that the tip of Valve-inlet needle is not worn.
Replace it the new one if it looks worn.
Check that Lever-metering is not worn and it is assembled
properly as drawn in
Fig
.
31
.
Note
: Low position of Control lever causes;
• Insufficient fuel circulation
• No maximum power
High position of Control lever causes;
• Carburetor flooding
• Starting problems
• Poor idling
• Poor acceleration
If necessary, reassemble them properly / replace them with
the new ones.
• When Diaphragm-pump is dented, torn, or creased,
• When the valve flaps of Diaphragm-pump are bent,
replace Diaphragm-pump and Gasket-pump with new ones.
• (i) When Diaphragm assembly-metering is dented, hardened,
or torn,
(ii) If there is a visible wear on the button of Diaphragm
assembly-metering
• If Diaphragm assembly-metering lacks elasticity, replace
Diaphragm assembly-metering and Gasket-metering diaphragm
with new ones.
Connect 1R127
to the fuel nipple.
1R127
Push
Carburetor
Spring
Plug-welch
Lever-metering
Pin-metering lever
Valve-inlet needle
Inlet screen
Diaphragm-pump
Gasket pump
Gasket-metering
diaphragm
Diaphragm
assembly-metering
Pulse hole
Screw-idle adjustment (S)
Needle-idle
L
Needle-high speed
H
Correct
Too high
Too low
(Position of Lever-metering)
ZAMA
Walbro
1-1/4
1-1/2
2
4-1/4
L-needle
H-needle
Note
: Adjust the rpm from the above setting positions with 1R070.
