162fmj Engine Service Manual -

Single-cylinder, 4-stroke, air-cooled, OHV (Pushrod). Displacement: 149.4cc. Bore x Stroke: 62.0 mm × 49.5 mm. Compression Ratio: 9.2:1. Cooling System: Natural air cooling. Starter System: Kick starter and/or electric starter. Service Clearances & Tolerances Intake Valve Clearance (Cold): 0.05 mm (0.002 in). Exhaust Valve Clearance (Cold): 0.05 mm (0.002 in). Spark Plug Gap: 0.6 mm – 0.7 mm. Engine Oil Capacity: 0.9 Liters (1.0 Liter at disassembly).

: This section usually provides an overview of the engine, including its design features, technical specifications, and application areas.

Inspect the spark plug, clean carbon deposits, and check the gap (standard gap is typically 0.6 - 0.7 mm).

Install rings with the stamped markings (e.g., "T" or size marks) facing up . Space the ring gaps 120 degrees apart so they do not line up. 162fmj Engine Service Manual

Dirty or low oil is the primary cause of engine failure in 162FMJ units.

Remove the carburetor to clean the main jet and pilot jet if the engine struggles to idle or accelerate. 4. Troubleshooting and Repairs 4.1. Engine Will Not Start

The 162FMJ is one of the most reliable and widely produced single-cylinder motorcycle engines in the world. Originally based on classic Japanese overhead valve (OHV) geometry, this 150cc air-cooled workhorse powers millions of commuter motorcycles, dirt bikes, ATVs, and go-karts. Single-cylinder, 4-stroke, air-cooled, OHV (Pushrod)

| Specification | Standard Value | Notes / Variants | | :--- | :--- | :--- | | | Single Cylinder, 4-Stroke, Air-Cooled, Vertical | CG-style engine design | | Displacement | 149.4 cc (approx. 150cc) | 62 mm bore; 49.5 mm stroke | | Compression Ratio | 9.0:1 to 9.8:1 | Varies by manufacturer (e.g., 9.8:1 for CBP150 version) | | Max. Power | 8.5 - 9.2 kW @ 8500 rpm | Up to ~12.3 hp (9.2 kW) for high-performance variants | | Max. Torque | 10.4 - 11.0 Nm @ 7500 rpm | High-torque version available (11.0 Nm) | | Bore & Stroke | 62.0 mm x 49.5 mm | Square, over-square design for good power balance | | Ignition | Capacitor Discharge Ignition (CDI) | Electronic, no moving parts, highly reliable | | Lubrication | Pressure / Splash | Combined system with oil pump for reliability | | Starting | Electric & Kick Start | Both systems present on most variants | | Transmission | 5-Speed, Manual, Wet Clutch | "1-down, 4-up" shift pattern on most bikes | | Oil Capacity | ~1.1 L (1100 ml) | 1.0 L to 1.3 L range depending on engine case |

Use a 10mm wrench and a tappet adjustment tool to set the clearance, then lock the nut. 3.3. Carburetor Maintenance (Idle Speed) Idle Speed:

The 162FMJ engine, a 150cc single-cylinder, air-cooled four-stroke overhead valve (OHV) powerhouse, is a staple of the "CG" engine family. Known for its remarkable durability and simplicity, it powers millions of commuter motorcycles and utility vehicles worldwide. However, even the most robust machinery requires precise maintenance. The service manual for the 162FMJ serves as the definitive roadmap for technicians and hobbyists, bridging the gap between mechanical intuition and manufacturer-specified precision. The Role of Technical Specifications Compression Ratio: 9

Ensure there is 2–3mm of free play at the clutch handlebar lever.

The 162FMJ is widely used in Chinese-manufactured vehicles. Parts are readily available on sites like Scribd . When ordering parts, always confirm the "CG150" designation. Spark plug wrench, sockets, Feeler gauge, Torque wrench.

Remove the cylinder head (OHV, so the cam stays in the block).

Regular maintenance prevents premature wear on pushrods, valves, and transmission gears. Follow these intervals closely. Oil Change and Screen Cleaning