GX25 Engine Assembly Information

CRANKSHAFT/PISTON LOWER CRANKCASE PISTON RING 4 x 8 mm SCREW (2) CARBURETOR SIDE REASSEMBLY: REASSEMBLY: WASHER (Serial number: GCAAM-1001494 ～) · Install the second ring with the " • " mark facing up. Clean the threads and apply liquid · Do not interchange the top ring and the second ring. sealant ( Loctite® 648, Hondalock 2 12.3 x 2.4 mm O-RING · After assembly, check for smooth movement of the piston rings. or equivalent ) to the threads. · Stagger the piston ring end gaps 120° apart. Do not align with the piston pin. OIL OUTLET VALVE PLATE · Space the oil ring side rail end gaps at least 10 mm (0.4 in) apart. INSTALLATION: Coat the oil ring with oil after assembly. Install the oil outlet valve to the oil outlet valve plate SHROUD D12 TUBE CLIP TOP RING by aligning the chamfer (Color: Gold) (CHROME FACE) and projections. SECOND RING (BLACK FACE) TOP RING 5 x 16 mm HEX BOLT (3) OIL RINGS SIDE RAIL OIL OUTLET SECOND RING (COMBINATION SPACER VALVE REASSEMBLY: OIL RINGS STOPPER Clean the hex bolt threads and RINGS) SIDE RAIL OIL PROJECTIONS PLATE apply liquid sealant (Loctite® 648, FILLER " • " MARK Hondalock 2 or equivalent) to the " △ " MARK CHAMFER CAP PISTON PIN threads. TOP RING 10 x 20 x 5 mm OIL FILLER CAP PACKING OIL TUBE OIL SEAL D13 TUBE CLIP LOWER CRANKCASE SECOND RING 3.5 mm SCREW (Color: Silver) 12 x 24 x 5 mm REASSEMBLY: OIL RINGS OIL SEAL PISTON Clean the inside of the crankcase 5 x 20 mm HEX BOLT (2) (COMBINATION REASSEMBLY: and remove foreign material before 6.4 N·m (0.65 kgf·m, 4.7 lbf·ft) RINGS) Install with the " △ " mark reassembly. on the piston head facing 5 x 30 mm HEX BOLT (4) 10 mm (0.4 in) the carburetor side. 6.4 N·m (0.65 kgf·m, 4.7 lbf·ft) CRANKSHAFT

CAM PULLEY/CRANKSHAFT LOWER CRANKCASE/CYLINDER BARREL/VALVES CAM PULLEY CAM PULLEY LOWER CRANKCASE VALVE SPRING ALIGNMENT VALVE SPRING (2) CYLINDER RETAINER (2) TIMING BELT MARKS BARREL VALVE STEM SEAL DISASSEMBLY: CAM PULLEY (Intake valve only) Do not remove the TIMING BELT SHAFT Do not reuse. valve spring retainers while the lower VALVE LIFTER (2) crankcase is installed, Do not or the valves will drop disassemble. into the cylinder. CAM PULLEY SHAFT HEAD COVER MATING SURFACE VALVE ROCKER SPARK PLUG FLYWHEEL Loosely tighten two 5 x 20 mm ARM (2) PISTON LIQUID GASKET Do not CMR5H (NGK) and four 5 x 30 mm hex bolts, APPLICATION AREA disassemble. (Hondabond 4, and then tighten to the CYLINDER BARREL INSTALLATION: ThreeBond® #1216, numbered sequence. ・Check that the belt 1216E or equivalent) INTAKE VALVE is not worn or TORQUE: 6.4 N·m (0.65 kgf·m, EXHAUST VALVE cracked, and do not REASSEMBLY: Assemble within 3 4.7 lbf·ft) VALVE HEAD DIAMETER: bend or twist the Do not interchange with minutes after applying Wait for approximately 60 EX: 12.5 mm (0.49 in) belt. the exhaust valve. the liquid gasket. minutes after assembly before ALIGNMENT ・Install with the filling with oil and starting the VALVE HEAD FAN COVER BOLT HOLE ▽ MARK markings as shown. CRANKSHAFT engine. DIAMETER: