Engine losing power over time:
Air temperature/humidity
changing compression
If air much cooler, add glow plug washer; if much
warmer, remove washer.
Dirt particle scratched
cylinder wall or crankshaft
seal
Replace piston/cylinder or crankcase.
“Varnish” buildup on
piston/cylinder (looks light
brown)
Remove varnish (a byproduct of over-heated
castor oil) with 3M Scotchbright cloth or fine
steel wool. Never use sandpaper!
Crankcase back plate not
tight
Remove engine and back plate, apply thread
lock (temporary type) sparingly to back plate
threads and reassemble.
Old engine naturally
wearing out
Replace engine.
Engine sound “warbles” (oscillates) at high throttle, overheats:
Main rotor blade pitch too
high, engine overloaded
Change one blade grip to lower blade pitch and
re-track rotor blades.
Compression too high,
fuel pre-detonating
Add glow plug washer(s).
Bad ball bearing on main
rotor or tail rotor
Replace bearing (bad bearing may not be
noticeable when turned by hand, or may feel
slightly gritty).
Gear mesh too tight/ too
loose
Remesh gears. Make sure engine mounting
bolts are tight.
Gyro dragging
Relubricate gyro hub and gyro spindle.
Rotor head not balanced
(everything shaking)
Rebalance rotor head.
Rotor blades not tracking
(everything shaking)
Track rotor blades.
Main shaft bent
(everything shaking)
Remove main rotor from main shaft. Attach
paper clip wire or other pointer to fuselage keel
and rotate shaft by pointer to determine direction
of bend. Press firmly on top of shaft with thumb
in direction opposite of bend. Repeat procedure
until shaft is straight. Reassemble main rotor.
Engine sound oscillates at all throttle settings:
Clutch shaft loose, clutch
shoes slipping against
prop plate
Tighten clutch shaft in end of engine crankshaft.
Op er a tor's Guide
Trouble-Shooting Glow Engines
9-4
LITE MA CHINES
