WACO YMF F5 Series, Руководство по обслуживанию

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WACO Classic Aircraft Corporation
YMF WACO F5 SERIES MAINTENANCE MANUAL
REVISION: H Page
28
of
33
RELEASED: 07/21/2017 PART NO. YMFAMM-1
RUNNING-IN
All Jacobs engines are thoroughly tested and run-in at the factory. However, a hone-hour check run should be
made before flight, to check the installation.
Before starting, turn the propeller at least six complete turns by hand to determine that there is no oil or
gasoline accumulated in the lower cylinders.
If rust preventative oil has not been previously drained from the cylinders, all plugs must be removed
from rear spark plug holes. The engine must then be turned slowly by hand at least ten revolutions to
drain the rust preventative oil. The engine should again be rotated several revolutions after reinstallation
of the spark plugs.
After the engine has been started, the oil pressure and fuel pressure should be immediately checked. The engine
should be run-in at 600 RPM to 1000 RPM. Set controllable propellers in low pitch.
After the oil is warm, check the oil and fuel lines, cowling, baffles and controls.
In order to avoid overheating during the check run, a gasket type thermocouple should be installed under one of
the rear spark plugs, and the temperature closely observed. The oil temperature should not be permitted to
exceed allowable limits. The head temperature should not be permitting to exceed 400° F (200° C) except when
opening the throttle to check maximum engine speed, when a maximum temperature of 450° F (232° C) is
permissible.
DO NO
T “REV-UP” THE ENGINE UNTIL THE OIL HAS BEEN THOROUGHLY HEATED AND A SUFFICIENT
LENGTH OF TIME ALLOWED FOR ALL PARTS TO BECOME THOROUGHLY LUBRICATED. THE
“REVVING-UP” SHOULD NOT TAKE PLACE UNTIL THE ENGINE IS READY FOR FLIGHT AND SHOULD
NOT EXCEED 20 SECONDS.
”
7.4 COMPRESSION TESTING OF ENGINE CYLINDERS:
Using the Differential Compression Test method described in FAA Advisory Circular AC 43.13-
1B CHG 1, paragraph 8-14(a), test to determine the internal condition of the combustion
chamber cylinder assembly by ascertaining if any appreciable internal leakage is occurring. If a
cylinder has less than a 60/80 reading on the differential test gauges on a hot engine, the
cylinder must be removed
and inspected. To determine the cylinder’s problem area, have
someone hold the propeller
at the weak cylinder’s top dead center and with compressed air still
being applied, listen. If air is heard coming out of the exhaust pipe, the
cylinder’s exhaust-valve
is not seating properly. If air is heard leaking out of the air cleaner/carburetor heat box, the
intake valve is leaking. If air is heard coming out of the engine crankcase breather tube, the
piston rings are defective. Remove and repair/overhaul the defective cylinder.
7.4.1 When the spark plugs are removed from the engine, identify them to coincide with the cylinder
and location from which they were removed. Close examination of the plugs will reveal the
actual operating conditions and aid in diagnosing problems within each individual cylinder.
7.4.2 The operating and maintenance records of the engine should be reviewed. Records of previous
compression tests are of assistance in determining progressive wear conditions and help to
establish the necessary maintenance corrective actions.