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If proper tire pressure
Ensure airflow is free of
blockage/restriction.
Verify proper tuning of carburetor (refer to
TECHNICAL GUIDE FOR 50cc
CARBURETORS for proper
procedure/specifications) and replace spark
plug.
If tire pressure is low
Inflate to recommended pressure.
Check for leaks or improper valve stem.
Ensure airflow is free of
blockage/restriction.
Verify proper tuning of carburetor (refer to
TECHNICAL GUIDE FOR 50cc
CARBURETORS for proper
procedure/specifications) and replace spark
plug.
If the spark plug appeared light gray in color, this indicates that the engine may be running
hot, possibly causing detonation or may have poorly maintained and or poor oil quality.
Inspect vehicle oil.
Oil meets requirements
Verify sufficient flow and operating
temperature.
Oil does not meet requirements
(Over full, low, or burnt/dirty oil)
Perform engine oil change.
Verify sufficient operating temperature.
Temperature is within range
Perform ENGINE COMPRESSION TEST
(refer to guide for proper procedure and
specifications).
Temperature is too high
Inspect for excessive carbon buildup in
combustion chamber, then perform
ENGINE COMPRESSION TEST (refer
to guide for proper procedure and
specifications).
If the symptom has persisted to this point, KEEWAY recommends disassembly of the
cylinder head and inspection for proper lubrication, verification of carbon buildup, and a
potentially warped/uneven surface. Inspect the piston assembly and cylinder jug for the same
signs. A lubrication issue will denote either blockage in the lines or a bad oil pump. Take
the appropriate action and reinstall with new gaskets (see guide for proper procedure and
specifications). If the symptom continues beyond this point, engine timing is most likely out
of range.
