152fmh Engine Service Manual [top] Today
Space the ring gaps 120 degrees apart from one another around the piston circumference. Never place a ring gap over the wrist pin holes or directly in line with the piston thrust face (top or bottom).
The pilot jet inside the carburetor is clogged with varnish or debris. Remove the carburetor bowl and clean the jet holes with compressed air and fine copper wire.
Thoroughly wash and clear the exterior cylinder cooling fins. Worn piston rings or scored cylinder
Before performing any service work, verify your engine code. The code "" is stamped into the lower left crankcase, near the gear shift lever. Decoder Ring 1 : Single cylinder 52 : 52.4mm cylinder bore F : Natural air cooling M : Motorcycle/powersports application H : 110cc displacement class Technical Data Sheet Specification Engine Type Horizontal, Single-Cylinder, 4-Stroke, SOHC Displacement 107cc (commonly marketed as 110cc) Bore x Stroke 52.4 mm x 49.5 mm Compression Ratio 9.0:1 to 9.7:1 Cooling System Forced Air Cooled Ignition Type CDI (Capacitor Discharge Ignition) Spark Plug NGK C7HSA or A7TC (Gap: 0.6mm - 0.7mm) Clutch Type Wet multi-plate (Automatic Centrifugal or Manual) Transmission 3-Speed with Reverse, 4-Speed Manual, or Full Auto Engine Oil Capacity 0.8 Liters (0.84 US quarts) Recommended Oil SAE 10W-40 JASO MA/MA2 (Wet-clutch compatible) 2. Routine Maintenance Schedule
Main Jet: #75–#78 | Pilot Jet: #32–#35 Adjusting the Idle Mixture: Start the engine and let it reach operating temperature. 152fmh engine service manual
Check the primary resistance (terminal to ground, ~0.5 to 1.5 Ohms) and secondary resistance (spark plug cap to ground, ~3,000 to 8,000 Ohms). Replace if values read open or infinite. 7. Troubleshooting Engine Performance Issues
Looking to keep your 110cc pit bike or ATV running smooth? The 152FMH is a "bulletproof" workhorse, but only if you stick to the service schedule.
The CDI ignition system on the 152FMH is simple but requires solid electrical connections to function.
The 152FMH is characterized by its compact horizontal design and simple air-cooling system. 110cc. Engine Type: Single-cylinder, 4-stroke, air-cooled. Power Output: Approximately 7 HP (4.7 kW at 8,000 RPM). Space the ring gaps 120 degrees apart from
When reassembling, use a torque wrench to avoid stripping the soft aluminum casings. Cylinder Head Nuts: ~10-12 Nm. Drain Bolt: ~20-25 Nm. Flywheel Nut: ~38-40 Nm. Typhoon Blokhus ApS. Clutch Replacement (15-Minute Method)
Warm up the engine for 3–5 minutes to lower oil viscosity. Place a drain pan directly beneath the engine.
Ensure the main green wiring harness wire is securely fastened to a bare-metal spot on the engine block. Clean off any rust or paint. 7. Engine Top-End Disassembly and Rebuild
Before turning a wrench, verify your engine code. The code is typically stamped into the lower left side of the crankcase, near the gear shifter. Decoding the Engine Code 1 : Single cylinder 52 : 52.4mm cylinder bore F : Air-cooled by natural airflow M : Motorcycle/powersports engine H : 110cc displacement class Key Technical Data Engine Type: 4-Stroke, Single Cylinder, OHC, Air-Cooled Actual Displacement: 107cc to 110cc Bore x Stroke: 52.4mm x 49.5mm Compression Ratio: 9.0:1 or 9.1:1 Remove the carburetor bowl and clean the jet
If adjustment is required, loosen the locknut with a 9mm wrench.
Remove the cylinder head gasket and the rubber O-rings around the oil passages. Slide the cylinder block forward to expose the piston.
Before turning a wrench, it is vital to have the correct factory specifications. Using incorrect torque values can strip threads in the soft aluminum casings or cause catastrophic engine failure. General Specifications