Table of Contents
Advertisement
3. mGH OIL TEMPERATURE.
a. Insufficient cooling.
b. Insufficient oil supply, Should be 8 quarts.
c. Check oil for proper viscosity. (See lubrication
chart, page 5.
d. Check for excessively lean fuel mixtures.
4. LOW POWER.
a. Check ignition system in general.
b. Check for full opening of throttle and for proper
closing of carburetor air heater valve,
c. Check gasoline for proper octane and volatility.
Automobile gasolines regardless of octane rating are
unsuitable for use in aircraft engines, and will not
only cause loss of power and overheating but will re-
sult in serious damage.
d. Check for low compression in cylinders.
5. ROUGH RUNNING.
a, Check propeller for balance, pitch, track and
tightness of attaching bolts.
b. Remove and clean spark plugs. Set electrode gaps
as specified in Service Bulletin M77-IO. Test plugs in dry
compressed air.
c. Test for uneven cylinder compression by turning
propeller, with ignition switch "OFF", or, with a
gauge installed alternately in upper spark plug holes,
Crank engine with starter and compare indicated pres-
sures.
d. Test ignition cables for high tension breakdown.
e. Remove magnetos.
Test condensers, timing,
operation.
£. Remove carburetor; disassemble, clean, test it.
g, Check engine mount bolts and Lord bushings.
6. ENGINE FAILS TO ACCELERATE PROPERLY.
a. Engine not suffiCiently warm.
b. Mixture too lean (use "FULL RICH" on ground).
c, Carburetor idling jet mis-adjusted or plugged.
d. Carburetor accelerator pump inoperative.
e. Low octane fuel, water in fuel, dirty fuel.
f. Carburetor air heat valve improperly adjusted.
g, Air intake restricted.
Section 8
SERVICE INSPECTION AND ASSOCIATED
MAINTENANCE
1. DAILY INSPECTION.
a. Check oil and fuel levels and replenish
if
neces-
sary.
b. Check oil and fuel systems for leaks and plugged
vents. Remove any oil from exterior.
c. Check for free operation of throttle, mixture
control, and carburetor heat control. Clean fuel filter
bowl
if
necessary.
d. Check the entire engine for missing or loose nuts,
screws, bolts, etc.
e. Check safety wiring, baffles, and ignition system.
f. Check propeller for pits, cracks, nicks, and se-
curity of mounting.
g. The air filter should be checked daily for:
(1) Cleanliness.
(2) Condition of seals and gaskets.
(3) Condition of air box and ducting.
(4) Be absolutely sure that no air leaks exist in in-
duction system at any point that would allow unfiltered
air into engine.
2, lOO-HOUR INSPECTION.
a. Remove and inspect general condition of engine
cowling.
b. Wash the exterior of the engine thoroughly with
a good cleaning solvent.
This may be done with a
brush but spraying is preferable. Keep away from
electrical equipment.
c. Check engine mounting bolts and brackets for
tightness and security.
d. Remove rocker box covers and inspect general
condition of all parts. Interior of covers should show
complete coverage with oil for proper lubrication.
e. Check intake manifold, elbows and rubber con-
nections for condition and security.
f. Remove spark plugs, clean, check gap clearance
for being between. 015" and . 022", test and replace,
using solid copper gaskets.
g. Check all high tension cables and terminals for
condition and security.
h.
Check propeller for condition, security of mount-
ing and proper track.
Blades should track within
1/8 inch.
i.
Remove and clean sediment bowl and screen, re-
place, tighten and safety.
j. Remove drain plug from bottom of carburetor
float chamber, remove and clean strainer. Turn fuel
on and flush out any water or sediment or trapped air,
replace strainer and plug, safety same.
k. Check for full range movement of carburetor
throttle, mixture control lever and carburetor heater
control valve.
1. Check all air pressure baffles for cracks, posi-
tion and security of fastening.
m. Remove, clean in fresh cleaning solvent and in-
spect the carburetor air filter.
If
the flocking on the
surfaces is worn through so as to expose the metal
screen the filter will not be effective and must be re-
placed with a new part.
If
the original filter is satis-
factory, dry
it
thoroughly; then dip it in clean engine
lubricating oil, and allow
it
to drain for eight hours
or so before installing.
Inspect the air scoop for
cracks, deformation of the air filter retaining parts
and obstruction of the drain tube.
Repair or replace
parts as necessary to correct such conditions.
n. Remove oil screens from bottom of crankcase
cover. Clean, inspect and replace them.
Use new
gaskets,
o. Remove magneto breaker cover and thoroughly
clean and dry the breaker mechanism; check contact
pOints for condition in general. (See Section on Mag-
netos for further instructions. )
p. Check the exhaust system for cracks or looseness
in mounting and connections.
Check exhaust port for
blown gaskets. Check cabin heater for any possibility
of exhaust gas leaks.
17
Advertisement
Table of Contents
