9 Higher temperature expands the air with its
resultant reduced density.
9 Higher humidity reduces the amount of oxygen
in the air by so much of the water vapor in the
9 Lower atmospheric pressure (at a high altitude)
reduces the density of the air.
After warming up the engine equipped with the
standard type carburetor(s) and spark plug(s),
run two or three laps of the circuit and check the
smooth operation of the engine and discoloration
of spark plug(s).
∫ Over burned (too lean)
ç Oil fouled (too rich)
Condition of spark plug
Insulator is dry and
Insulator is whitish.
Insulator is sooty and