GX240 ・ GX270R/RT/T/U/UT
GX340 ・ GX390K1/R1/T1/U1/UT1
Engine Adjustment Information
GOVERNOR
①. Remove the fuel tank.
②. Loosen the nut on the governor arm and move the governor arm to fully open the throttle.
③. Rotate the governor arm shaft as far as it will go in the same direction the governor
arm moved to open the throttle. Tighten the nut on the governor.
④. Start the engine and allow it to warm up to normal operating temperature.
Determine the point where the engine runs at the standard maximum speed by moving
the throttle lever. Then using the special tool, adjust the maximum engine speed by
turning the 5 x 25 mm torx. bolt so that the throttle lever cannot be moved past that point.
Maximum engine speed: 3,850 ± 150 min-1 (rpm)
5 x 25 mm TORX. BOLT
NUT
5 x 25 mm
TORX. BOLT
GOVERNOR
ARM SHAFT
THROTTLE LEVER
VALVE CLEARANCE
NOTE: Valve clearance inspection and adjustment must be performed with the engine cold.
①. Remove the cylinder head cover and recoil starter.
②. Turn the crankshaft and set the piston at top dead center of the compression stroke
(both valves fully closed). The triangle mark on the starter pulley will align with the top
hole on the starter cover when the piston is at top dead center of the compression or
exhaust stroke.
③. Insert a feeler gauge between the rocker arm and valve to measure valve clearance.
Valve clearance: 0.15 ± 0.02 mm (IN)
0.20 ± 0.02 mm (EX)
④. If adjustment is necessary, proceed as follows:
a. Hold the rocker arm pivot and loosen the rocker arm pivot lock nut.
b. Turn the rocker arm pivot to obtain the specified clearance.
c. Retighten the rocker arm pivot lock nut while holding the rocker arm pivot.
TORQUE: 10 N·m (1.0 kgf·m, 7 lbt·ft)
d. Recheck valve clearance after tightening the rocker arm pivot lock nut.
2
TOP HOLE
3
CYLINDER HEAD
COVER BOLT
1
GASKET
4
FEELER GAUGE
CYLINDER
HEAD COVER
ROCKER ARM
ROCKER ARM
PIVOT
VALVE
ROCKER ARM
PIVOT LOCK NUT
ALIGN
・To increase valve clearance, screw out.
・To decrease valve clearance, screw in.
TRIANGLE MARK
IGNITION COIL AIR GAP
①. Loosen the ignition coil mounting bolts.
②. Insert a feeler gauge of proper thickness between the ignition coil and flywheel.
③. Push the ignition coil firmly against the flywheel and tighten the ignition coil mounting bolt. Remove a feeler gauge.
Specified gap: 0.4 ± 0.2 mm (0.016 ± 0.008 in)
NOTE: Avoid the magnet part of the flywheel when adjusting.
Adjust the gap equally at both ends of the ignition coil.
IGNITION COIL
IGNITION COIL
FLYWHEEL
0.4 ± 0.2 mm
(0.016 ± 0.008 in)
See the shop manual for additional information.
© Honda Motor Co., Ltd. 2010
Download PDF