152fmh Engine — Service Manual
For specific assembly diagrams, including the 1P52FMH-3 110cc, resources like MyPitbike.ru provide detailed diagrams and part numbers.
Before turning a wrench, confirm your engine identification code. The code is typically stamped into the lower left side of the crankcase, near the gear shifter. Decoding the 152FMH Engine Code: 1 : Single cylinder 52 : 52mm cylinder bore F : Natural air cooling M : Motorcycle/powersports engine H : 110cc displacement class Core Technical Specifications: Engine Type: 4-Stroke, Single Cylinder, Horizontal, OHC Displacement: 107cc (commonly marketed as 110cc) Bore x Stroke: 52.4 mm x 49.5 mm Compression Ratio: 9.0:1 or 9.1:1 Cooling System: Air-cooled Ignition Type: CDI (Capacitor Discharge Ignition) Spark Plug: NGK CR7HSA or A7TC (Gap: 0.6mm – 0.7mm)
The 152FMH is a small four-stroke gasoline engine commonly used in light-duty agricultural machinery, portable generators, small pumps, and other utility equipment. This manual covers identification, specifications, routine maintenance, troubleshooting, disassembly/reassembly, inspection, repair procedures, and parts considerations. Assumptions: engine is air-cooled, single-cylinder, overhead valve (OHV), 152 cc displacement, horizontal shaft configuration with recoil start and carburetor (typical for small utility engines of this class). Adjust procedures as needed for specific model variations. 152fmh engine service manual
Turn the square adjusting square pin until the feeler gauge fits with proper resistance.
4-speed constant mesh (Standard patterns: N-1-2-3-4 or All-Up) Decoding the 152FMH Engine Code: 1 : Single
Measures 300–600 Ohms to ground.
Warning: Never use automotive "Resource Conserving" oils containing friction modifiers. Step-by-Step Oil Change Procedure Adjust procedures as needed for specific model variations
Install a new head gasket. Position the cylinder head and tighten bolts to the factory torque specification using the proper sequence. Key Service Tips Most 152FMH engines use 10W-40 4-stroke motorcycle oil (JASO MA2 compliant if it has a wet clutch). Valve Timing:
Remove the cylinder head tappet caps (top and bottom). Remove the stator cover caps on the left side of the engine to expose the flywheel nut and timing marks.
Gently tap the cylinder head with a rubber mallet to break the gasket seal and slide it off the cylinder studs.
Warm up the engine for 3–5 minutes to lower oil viscosity. Place a drain pan directly beneath the engine.
