Makita EA3500S Technical Information page 11

R
epair
[2] DISASSEMBLY/ ASSEMBLY
[2]-10. Air filter, Carburetor, Intermediate flange (cont.)
Needle adjustment
See Figs. 29 and 30 for the positions of Needle-idle (L)
and Needle-high speed (H) .
After tightening each Needle to the full;
• unscrew Needle-idle (L) one and a half turns.
• unscrew Needle-high speed (H) four turns.
Note: Adjust the rpm from the above setting positions
with 1R070.
Pressure test
(1) Connect 1R127 to Carburetor. (Fig. 30)
(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. 31)
• Dirt/ deposits on the top of Valve-inlet needle: clean it.
• Gasket pump and Diaphragm-pump: replace them
with the new ones.
General check
• Inlet screen should be clean.
• Pulse hole should be clean.
Check around Valve-inlet needle and Lever-metering
Refer to Figs. 31 and 32.
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. 30.
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.
Check Diaphragm-pump
• 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.
Check Diaphragm assembly-metering
• (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 the new ones.
Fig. 29
(S) L
Fig. 30
Carburetor
Connect 1R127
to the fuel nipple.
Fig. 31
Screw-idle adjustment (S)
Needle-idle
L
Needle-high speed
H
Spring
Lever-metering
Pin-metering lever
Plug-welch
Gasket-metering
diaphragm
Diaphragm
assembly-metering
Fig. 32
(Position of Lever-metering)
Correct Too high
P 11/ 16
H
Push
1R127
Pulse hole
Gasket pump
Diaphragm-pump
Inlet screen
Valve-inlet needle
Too low