: Check the CDI unit, ignition coil, and spark plug gap [27]. Clutch Slippage
Accurate specifications prevent component damage during reassembly. Use these precise metrics for your maintenance work. Component / Metric Specification Single-cylinder, 4-stroke, air-cooled, horizontal Displacement 119.7cc (commonly referred to as 125cc) Bore x Stroke 54 mm x 54 mm Compression Ratio Maximum Power ~8.5 hp (6.3 kW) @ 7500 RPM Maximum Torque 8.8 Nm @ 5500 RPM Clutch Type
Oil is the lifeblood of this air-cooled engine. Because it lacks a large oil cooler, the lubricant breaks down quickly under high-heat conditions. : Approximately 900ml [31]. Recommended Grade
Valve lapping, piston ring replacement, and cylinder honing. lifan 1p54fmi service manual
Remove the two view plugs on the left-side stator cover. Remove the round valve inspection caps on the top and bottom of the cylinder head.
Procedure: Rotate the crankshaft to Top Dead Center (TDC) on the compression stroke (both rocker arms loose). Use a feeler gauge between the rocker arm screw and valve tip. Loosen locknut to adjust.
The is a rugged, single-cylinder, four-stroke engine commonly found in small-displacement motorcycles, pit bikes, ATVs, and scooters (notably the Lifan 125cc–140cc family). Understanding its design and maintenance requirements is essential for reliability and performance. : Check the CDI unit, ignition coil, and spark plug gap [27]
9.0:1 or 9.3:1 (depending on the exact production batch) Maximum Power: ~8.5 hp (6.3 kW) @ 7,500 RPM Maximum Torque: 8.8 Nm @ 5,500 RPM
Drain the engine oil and remove the carburetor, exhaust pipe, and spark plug. Remove the left-side cam gear cover.
This guide covers 95% of user-serviceable needs for the 1P54FMI. For transmission overhaul, crankshaft replacement, or gear shifting issues, you will need the or professional assistance. or gear shifting issues
Ensure 3mm–5mm of free play at the handlebar clutch lever.
9.0:1 or 9.3:1 (depending on production year) Clutch Type: Wet, Multi-plate (Manual or Semi-Automatic) Ignition: CDI (Capacitor Discharge Ignition) Torque Specs (Critical Fasteners) Cylinder Head Nuts: 10–12 ft-lbs (14–16 Nm) Flywheel Nut: 30–33 ft-lbs (41–45 Nm) Stator Plate Screws: 5–7 ft-lbs (7–9 Nm) Oil Drain Plug: 15 ft-lbs (20 Nm) 2. Routine Maintenance Schedule