Single-cylinder, 4-stroke, air-cooled, OHV (Pushrod) Displacement: 149.4cc Bore x Stroke: 62.0 mm × 49.5 mm
Change engine oil, clean air filter, check spark plug condition.
Though an OHV engine has a short chain driving the cam from the crank. The manual specifies that the cam chain tensioner (automatic or manual) must be reset. Failure to do this causes the infamous 162FMJ "rattle."
Check and adjust valve clearance, inspect clutch cable freeplay, clean oil centrifugal filter. 162fmj Engine Service Manual
For deep repairs or rebuilding, you can reference these specialized documents:
JASO MA or JASO MA2 (Crucial for wet clutches. Do not use automotive oil with "Energy Conserving" friction modifiers, or your clutch will slip). Cleaning the Dual-Filter System
Understanding the factory specifications is critical before attempting any measurements or parts replacements. Specification Single-Cylinder, 4-Stroke, Air-Cooled, OHV Displacement Bore x Stroke 62.0 mm x 49.5 mm Compression Ratio 9.0:1 or 9.2:1 (variant dependent) Cooling System Natural Air Cooling Ignition Type CDI (Capacitor Discharge Ignition) Spark Plug Type NGK D8EA or Torch D8TC Spark Plug Gap 0.6 mm – 0.7 mm Lubrication System Pressure/Splash (Wet Sump) Oil Capacity 0.9 Litres (1.0 Litre at disassembly) Clutch Type Wet, Multi-Plate Transmission 5-Speed Constant Mesh 2. Periodic Maintenance Schedule Failure to do this causes the infamous 162FMJ "rattle
This engine is largely based on CG-type overhead valve (OHV) design, meaning it uses pushrods rather than an overhead camshaft (OHC). This design is highly robust and easier to maintain for beginners. 2. Routine Maintenance Schedule (Per Service Manual)
Before diving into repairs, you must know the core metrics of your specific machine. While some factory variations exist depending on whether the unit features a balance shaft, standard specs generally include the following: Manuals+https://manuals.plus
, including the use of 10W-40 or 15W-50 oil and instructions for checking the oil level via the sight glass. CDI Troubleshooting : Electrical diagrams and testing procedures for the Capacitor Discharge Ignition (CDI) inspect clutch cable freeplay
The 162FMJ uses a pushrod system, which generally requires more frequent adjustments than OHC engines.
Because the 162FMJ features an expanding pushrod configuration, keeping your valve clearances within spec is absolutely essential for smooth operation and preventing hard-starting conditions. : The engine must be completely stone-cold.