Engine Identification and Inspection
Cubic Inch Displacement Formula
3.14 * bore^2 * stroke * number of cylinders / 4
Combustion chamber
Area between the piston and cylinder head when the piston is at the top of its stroke
Multi-Position Crankshaft
Can be used at any angle Chainsaw; Weed Eater
A Two-stroke cycle engine
Carburetor may be located at the base of the cylinder or the bottom or side of the crankcase
A four-stroke cycle engine
Carburetor will always be on or near the cylinder head
Cycle
Completion of a series of events to produce a power impulse
A four-stroke cycle engine
Compression resistance is felt every other revolution
A Two-stroke cycle engine
Compression resistance is felt every revolution
Horizontal Crankshaft
Crankshaft lays horizontally
Vertical Crankshaft
Crankshaft on bottom, lawnmower
A Two-stroke cycle engine
Does not have an opil sump and oil filter
Two-stroke cycle engine
Engine design permiting a power stroke once for each revolution of the crankshaft
Four-stroke cycle engine
Engine design which develops a power stroke every other revolution of the crankshaft
A four-stroke cycle engine
Exhaust muffler connects at the head of the engine cylinder
A Two-stroke cycle engine
Exhaust port is about midpoint on the cylinder
Crankcase
Housing for the crankshaft and other related internal parts
Nameplate
Information plate attached by the manufacturer giving their name, the engine make, model, serial number, and other information
Intake port
Opening into the combustion chamber for the intake of the fuel-air charge
Exhaust port
Opening to the outside of the combustion chamber for the release of exhaust gases
A four-stroke cycle engine
Usually has oil sump and possibly and oil filter
Model numbers
describe the basic engine
The type number
describes the varations of the engine and these numbers are required when ordering parts
The code number
indicates the date the engine was built and assembly line number making the engine