Makita EK7650H Technical Information page 19

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[4] DISASSEMBLY/ASSEMBLY
[4]-9. Ignition system (cont.)
CHECKING SPARK PLUG
WARNING !!
• When a spark is produced, high-voltage current is delivered from Ignition coil to Spark plug.
It is, therefore, very dangerous to pull Recoil starter knob with your hand on Ignition cable.
Be sure to keep your hands off from Ignition cable when checking for spark.
• Fuel is extremely flammable and fuel vapors are explosive.
Therefore, clean up spilled fuel before starting to check for spark.
Also, be careful not to do the check near Carburetor.
(1) Remove Plug cap from Spark plug, then Spark plug from Cylinder head complete with the supplied socket wrench.
Note: If the electrodes of Spark plug are wet, wipe them with a rag then dry them with an air blower.
(2) Using a wire brush, carefully clean up carbon deposits (if any) from the electrodes and the ceramic insulator around
the center electrode.
(3) Adjust the electrode gap to 0.5mm by carefully bending the side electrode.
Use Feeler gauge set (1R366) to check the gap width:
between the center electrode and the side electrode, insert 0.5mm leaf
of Feeler gauge set. (Fig. 42)
(4) Install another Spark plug into spark plug hole to prevent air/fuel mixture
from leaking outside of engine.
(5) Connect the removed Spark plug with Plug cap, then ground the threads
of Spark plug to a proper metal part of the engine.
(6) With Stop switch on, pull Recoil starter knob gently and check for spark.
Note: It is hard to see the spark in a bright location.
Therefore, be sure to do the check in a shady but well-ventilated place.
(7) If spark is not produced, replace Spark plug with a new one,
then check for spark by following the procedure (1) to (6) once again.
[5] Tightening torque specifications
Application
(for fastening A to B)
A
1 Cushion
2 Cutting arm
3 Cutting arm
4 Front inner holder
5 Crank case
6 Cylinder head complete
7 Flywheel
8 Clutch holder
9 Clutch assembly
10 Rocker arm
B
Tank complete
Cylinder block complete
Belt cover
Cylinder block
Cylinder block
Crankshaft
Crankshaft
Crankshaft
M5 Hex socket head bolt
Fig. 42
side electrode
Fastener
M6x30 Hexalobular socket head bolt
M6x25 Hexalobular socket head bolt
M8 Hex nut
M6x30 Hexalobular socket head bolt
M6x30 Hexalobular socket head bolt
M6x35 Hexalobular socket head bolt
M10 Flange nut
Hexagonal portion (M16-24) of Clutch holder
M10-17 Hex lock nut
M5x9 Hex nut
P 19/ 19
Electrode gap
must be 0.5mm.
center electrode
Tightening
torque (N.m)
7
30
3
12
12
40
38
18
6