Failure Of Engine To Idle Properly; Low Power And Uneven Running - Lycoming O-320 76 Series Operator's Manual

SECTION 6
TROUBLE-SHOOTING
TROUBLE

Failure of Engine to Idle Properly

Low Power and Uneven Running

6-2
LYCOMING
PROBABLE CAUSE
Incorrect idle mixture.
Leak in induction system.
Incorrect idle adjustment.
Uneven cylinder compression.
Faulty ignition system.
Insufficient fuel pressure.
Mixture too rich indicated by
sluggish operation. Red exhaust
flame at night. Extreme cases
indicated by black smoke from
exhaust.
Mixture too lean; indicated by
overheating or backfiring.
Leaks in induction system.
Defective spark plugs.
Improper fuel.
Magneto breaker points not
working properly.
Defective ignition wire.
Defective spark plug terminal
connectors.
Warped exhaust valve.
SERIES OPERATOR'S MANUAL
REMEDY
Adjust mixture.
Tighten all connections in the
induction system. Replace any
parts that are defective.
Adjust throttle stop to obtain
correct idle.
Check condition of piston rings
and valve seats.
Check entire ignition system.
Change fuel pump.
Readjustment of carburetor by
authorized personnel is indicated.
Readjustment of carburetor by
authorized personnel is indicated.
Tighten all connections. Replace
defective parts.
Clean and gap or replace spark
plugs.
Fill tank with fuel of
recommended grade.
Clean points. Check internal
timing of magnetos.
Check wire with electric tester.
Replace defective wire.
Replace connectors on spark plug
wire.
Check compression. Replace
valve if necessary.
O-320