Worn piston rings or degraded valve stem seals causing oil bypass.
Drain from the left-side bottom plug; clean the reusable oil screen located behind the large cap on the right bottom.
Reinstall the cap with a fresh gasket, tighten the screws firmly, and reinstall the clutch cover. 5. Fuel System and Carburetor Tuning
Use a feeler gauge to measure clearance between the rocker arm and valve tip. Intake Valve: Exhaust Valve:
Remove the oil drain plug at the bottom of the engine while warm.
The 162FMJ is a popular model of small-displacement, single-cylinder engine mass-produced in China. It’s the heart of countless motorcycles, ATVs, go-karts, and three-wheelers around the world. The "162FMJ" designation is a code that reveals its basic specs: 162fmj Engine Service Manual
: A known weak point is the valve stem seals (oil seals) . Owners often report that the original Chinese seals harden and fail prematurely. A common fix is to replace them with seals from a Daewoo Matiz (a small car), which fit perfectly and last much longer.
Clean the oil strainer screen and spring to remove metal debris.
The 162FMJ is prized for its , featuring a longer stroke relative to its bore (typically around 62 mm x 49.5 mm). This configuration prioritizes low-to-mid-range torque over high-speed horsepower, making it exceptionally responsive in stop-and-go city traffic and capable of carrying heavy loads. Standard Specifications: Displacement: 149cc to 162cc.
Preventative maintenance prolongs the lifespan of the pushrod design. Follow these intervals closely.
Unlike standard modern Japanese engines, the 162FMJ does not use a paper oil filter cartridge. Instead, it relies on a and a crankshaft-mounted centrifugal oil filter trap to separate metal debris and sludge from the oil. Cleaning the Oil Screen Worn piston rings or degraded valve stem seals
Carbon accumulation on the piston crown and combustion chamber raising compression abnormally. Excessive Engine Noise
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: "Does this engine have 2 oil areas?"
Turn the pilot air/fuel mixture screw slowly clockwise until engine RPM drops, then turn it counterclockwise until the engine reaches its highest, smoothest RPM. Reset the idle speed screw back to 1,400 RPM. Engine Top-End Overhaul
Remove the drain bolt located at the bottom of the engine. The 162FMJ is a popular model of small-displacement,
SAE 15W-40 or 10W-40 4-Stroke Motorcycle Oil (JASO MA or MA2 rated for wet clutches). Cleaning the Filters:
: Every 2,000 km (more frequently in dusty areas). 3. Step-by-Step Service Procedures Valve Clearance Adjustment
Loosen the locknut with a 10mm wrench, turn the adjuster square-head pin until you feel a slight drag on the feeler gauge, and tighten the locknut while holding the pin steady.
Clogged carburetor jets, blocked fuel petcock, or vacuum leaks.