Lycoming YO-233-B2A - Page 98

TEO-540-A1A Engine Maintenance Manual
12-30 © 2021 Avco Corporation. All Rights Reserved
Page 78 February 2021
YO-233-B2A Engine Maintenance Manual
Table 1 (Cont.)
Fault Isolation Guide
Problem
Cause
Corrective Action
Ref.
Mixture control not
working
Faulty power switches
Replace the switches.
Faulty wiring in the
harness
Replace the harness.
Ignition Switch faulty
Check for faults on the ignition
switch circuits. Repair as
necessary.
Engine will not turn
static rpm or will not
develop rated rpm
Tachometer reading is
incorrect
1. Make sure that the tachometer
operates correctly.
2. Replace the tachometer.
OHM
Decreased air flow in the
air induction system
1. Examine the system and
remove all blockages.
2. Make sure that the airbox is
installed in accordance with
the airframe manufacturer’s
specifications.
Propeller is out of
adjustment (not reaching
specified low pitch)
Adjust in accordance with
propeller or airframe
manufacturer’s instructions.
Muffler’s internal baffles
are broken and blocking
the exhaust outlet
NOTICE: Broken
baffles can move around
freely in the muffler. The
engine may turn static
rpm’s intermittently.
1. Hit the muffler with a rubber
mallet or soft object.
2. Listen for a rattle which is
indication of loose baffles.
3. Remove the muffler and
complete the thorough
inspection.
4. Replace muffler as necessary,
in accordance with airframe
manufacturer’s instructions.
Air filter dirty
Replace air filter in accordance
with airframe manufacturer’s
instructions.
Too much air dropped
through a new air filter.
Defective air filter
1. Put the engine on test stand, in
a dust-free area.
2. Remove the air filter.
3. Operate the engine to full
throttle.
4. If the engine operates at full
rpm, replace the air filter with
a new air filter.