Engine
engine
Plain explanation
The heart of your Hunter 350 — a 349 cc air-cooled single-cylinder that converts fuel into motion through four strokes: intake, compression, combustion, and exhaust.
Technical
Single-cylinder SOHC four-stroke engine with electronic fuel injection. Air-cooled barrel and head with finned casting for heat dissipation. Integrates lubrication, ignition timing, and crankshaft power output to the clutch.
Function & location
Convert chemical energy in fuel into rotational mechanical power for the transmission.
Centrally mounted in the frame, below the fuel tank, above the exhaust header.
Connections
- Air intake and throttle body
- Fuel injectors
- Exhaust header
- Clutch assembly
- Electrical charging and ECU sensors
- Oil circulation system
Subcomponents
Cylinder
The metal sleeve where the piston moves up and down.
Cylinder head
The top section housing valves and spark plug.
Piston
Moves up and down inside the cylinder.
Connecting rod
Links piston to crankshaft.
Crankshaft
Main rotating shaft of the engine.
Camshaft
Controls valve opening timing.
Valves
Allow air/fuel in and exhaust out.
Spark plug
Creates ignition spark in the combustion chamber.
Fuel injector
Sprays metered fuel into the intake path.
Timing system
Synchronises camshaft and crankshaft.
Lubrication system
Oil pump, galleries, and filter circuit.
Engine casing
Outer crankcase and covers.
Oil filter
Filters engine oil contaminants.
Oil drain point
Sump plug for oil changes.
Common wear & symptoms
- Piston ring wear
- Valve seat recession
- Cam chain stretch
- Oil seal weeping
- Spark plug electrode erosion
- Loss of power
- Rough idle
- Excessive oil consumption
- Knocking under load
- Hard starting
Maintenance notes
- Monitor oil level and condition
- Follow verified oil change interval
- Inspect for external leaks
- Replace spark plug per schedule
Related guides
Related components
Demonstration content — verification required.