Honda gx120, gx160, gx200 Information Manual

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GX120 • GX160 • GX200 Engine Assembly Information

PISTON RING

REASSEMBLY:

· Install all rings with the markings facing upward.

· Be sure that the top and second rings are not interchanged.

· Check that the rings rotate smoothly after installation.

· Space the piston ring end gaps 120 degrees apart, and do not align the gaps with the piston pin bore.

· Space the oil ring side rail end gaps at least 10 mm (0.4 in) apart. Coat the oil ring with oil after assembly.

TOP RING (CHROME FACED)

SECOND RING (BLACK FACED)

OIL RING (COMBINATION RINGS)

CONNECTING ROD

REASSEMBLY: Install the

connecting rod with the long end toward the triangle-marked side of

the piston.

CRANKCASE COVER/CRANKSHAFT/PISTON

PISTON

REASSEMBLY:

Install with the triangle mark toward the

pushrod hole.

TRIANGLE MARK

PUSH ROD HOLE

OIL SEAL 22 x 35 x 6 mm (GX120) 25 x 41 x 6 mm

(GX160/GX200)

PISTON

PISTON PIN

VALVE LIFTER

REASSEMBLY:

Install the lifters immediately before

installing the camshaft.

MARKING

TOP RING (CHROME FACED)

SECOND RING (BLACK FACED)

OIL RING (COMBINATION RINGS)

PISTON PIN CLIP

REASSEMBLY:

Install by setting one end of the clip in the piston groove, holding the other end with long-nosed pliers, and rotating the clip in. Do not align the end gap of the clip with the cutout in the piston pin bore.

CLIP

CUT-OUT

CAMSHAFT

REASSEMBLY:

・With the crankshaft in place, align the

timing punch mark on the cam gear with the punch mark on the crankshaft gear.

・Before installing, inspect for worn and

weakened springs and check that the decompressor weight moves smoothly.

CYLINDER HEAD/VALVES

GX120/GX160:

VALVE ROTATOR (Exhaust valve only)

NOTICE:

If the valve rotator is not installed, the exhaust valve may drop into the cylinder

when starting the engine.

ROCKER ARM PIVOT (2)

ROCKER ARM PIVOT LOCK NUT (2)

10 N·m (1.0 kgf·m, 7 lbf·ft)

ROCKER ARM (2)

REASSEMBLY:

Before installing, check for wear on the surfaces which contact the pivot bolt, the push rod, and the rocker arm pivot.

INTAKE VALVE

REASSEMBLY:

· Do not interchange with the exhaust valve. Valve head diameter: Intake: 25 mm (0.98 in) Exhaust: 24 mm (0.94 in)

· Be careful not to damage the valve stem seal when installing.

VALVE SPRING RETAINER

DISASSEMBLY:

Push down and slide the retainer to the side, so the valve stem slips through the hole at the side of the retainer.

REASSEMBLY:

The exhaust valve retainer has a larger center recess than the intake valve retainer so it can accept the valve rotator.

NOTICE:

Do not remove the valve spring retainers while the cylinder head is installed, or the valves will drop into the cylinder.

CYLINDER HEAD

VALVE GUIDE (2)

VALVE SPRING (2)

ROCKER ARM PIVOT BOLT (2) 24 N·m (2.4 kgf·m, 17 lbf·ft)

GX200:

VALVE STEM SEAL (Intake valve only)

Replace with a new one when reassembling.

EXHAUST VALVE

REASSEMBLY:

・Before installation, remove carbon deposits

and inspect the valve.

・Do not interchange with the intake valve. VALVE HEAD DIAMETER GX120: IN: 22 mm (0.87 in) EX: 19 mm (0.75 in) GX160: IN: 25 mm (0.98 in)

EX: 24 mm

0.94 in

INTAKE VALVE

PUSH ROD (2)

REASSEMBLY:

Check both ends for wear, and check the rod for straightness. Be sure the rod ends are

firmly seated in the lifters.

Refer to the above for information not shown below.

GREAS

CRANKCASE

OIL DRAIN BOLT

18 N·m (1.8 kgf·m,

13 lbf·ft)

DRAIN BOLT WASHER

Replace.

CONNECTING ROD CAP

REASSEMBLY:

Install with the oil dipper toward the camshaft and the

See the shop manual for additional information. © Honda Motor Co., Ltd. 2009

ribs on the cap and connecting rod are aligned.

CONNECTING ROD BOLT

12 N·m (1.2 kgf·m, 9 lbf·ft)

GOVERNOR DRIVE GEAR

TIMING GEAR

CRANKSHAFT

REASSEMBLY:

Push in until the bearing touches the crankcase. Be careful not to

damage the oil seal.

BALL BEARING

PUNCH MARKS

CRANKCASE COVER

GASKET

Do not reuse.

OIL SEAL 22 x 41 x 6 mm (GX120)

25 x 41 x 6 mm (GX160/GX200)

CRANKCASE COVER

6 x 28 (GX120)

12 N·m (1.2 kgf·m, 9 lbf·ft)

8 x 32 (GX160/GX200)

24 N·m (2.4 kgf·m, 17 lbf·ft)

GREAS

CYLINDER HEAD

8 x 55 (4) (GX120), 8 x 60 (4) (GX160/GX200)

24 N·m (2.4 kgf·m, 17 lbf·ft)

REMOVAL/INSTALLATION:

Loosen and tighten the bolts in a crisscross pattern

in 2-3 steps.

DOWEL PINS

CYLINDER HEAD

REMOVAL/INSTALLATION:

· Before installation, remove any carbon deposits from the combustion chamber and inspect the valve seats.

· Measure the cylinder compression after reassembly.

GASKET

Do not reuse.

CYLINDER BARREL

GOVERNOR WEIGHT

REASSEMBLY: Be sure

to install the governor weight before installing the crankshaft.

CLIP

REASSEMBLY:

Insert firmly into the shaft

groove.

10 mm NUT

Green ( To side plate)

Yellow ( To engine switch)

GOVERNOR

GOVERNOR SLIDER

WASHER (2)

GOVERNOR

RM SHAFT

O-RING

REASSEMBLY: Install firmly in the groove.

REASSEMBLY:

The lock pin must be installed with the straight side of the pin against the groove in

the shaft.

OIL LEVEL SWITCH

WASHER

REASSEMBLY:

Install inside the case.

LOCK PIN

6 x 12 (2)

Printed In Belgium - Published by: Honda Motor Europe Logistics NV - Specifications can be changed without notice - Edition: 8302 Sept. 2017

www.honda-engines-eu.com