This maintenance information is provided to help you keep your new XL RFS series aircraft engine running in top form. Following this
maintenance information will ensure the long life and dependability you expect from your engine.
The valve clearances are preset from the factory, but do require periodic
adjustment. Reset the valves after the first 1 hour of engine run-time.
After that, the valves can be checked and adjusted about every 8 hours of
run-time. The valves will need adjustment if you notice a severe loss of
power or after you have repaired and/or reassembled the engine.
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IMPORTANT
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Always adjust the valves with the engine cold.
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1) With the engine cold, remove the rocker cover on top of the cylinder
head by unscrewing the two socket-cap screws.
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2) Rotate the crankshaft until the piston is at top-dead center. Both
valves will be closed at this point.
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3) The required valve clearance is between .04mm and .10mm,
measured between the valve stem and the rocker arm. Use feeler gauges
to check the clearance. The .04mm feeler gauge should pass through the
gap with only slight friction. The .10mm feeler gauge should be tight.
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4) Working with one valve at a time, loosen the locking nut, using a
small wrench. Use a screwdriver to turn the adjustment screw
counterclockwise about 1/2 turn. This will open the gap slightly. Slide the
.04mm feeler gauge between the rocker arm and the valve stem.
Carefully turn the adjustment screw clockwise until the rocker arm touches
the feeler gauge. Using a small wrench, tighten the lock nut.
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5) Remove the feeler gauge and double-check the gap. Repeat step
# 4 if necessary to achieve the correct setting, then repeat the process for
the second valve assembly.
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Use a high-quality after-run oil in the engine after you have purged the
engine of fuel. Inject the oil into the engine through the carburetor and
through the glow plug hole. Also, remove the fuel tubing from the intake
manifold and inject oil down into the cam gear. Rotate the crankshaft
several times to distribute the oil throughout the engine. This will prevent
rust from forming inside the engine, especially on the ball bearings.
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Wipe the outside of the engine dry using a soft cloth.
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Use a fuel filter between the fuel tank and the carburetor.
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Periodically check to make sure all of the engine bolts are tight,
including the muffler and exhaust pipe cinch nuts.
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Periodically check your fuel system, including the plumbing inside the
fuel tank, for leaks or cracks. We recommend changing the silicone fuel
tubing inside and outside the fuel tank at the start of every flying season or
about once a year.
Long-Term Storage
If you will not be using your engine for a long period of time, such as
during the winter, we suggest you take the following precautions to
preserve the reliability of your engine:
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Run the engine completely dry of fuel as described above. This is
extremely important.
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Remove the rocker cover and cam gear cover and apply a generous
amount of after-run oil on and around the rocker arm assembly and the
cam gear. Reinstall the covers.
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Remove the engine backplate and apply a generous amount of
after-run oil to the engine crankcase and to the rear ball bearing, then
reinstall the backplate.
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Apply a generous amount of after-run oil to the joint between the
carburetor barrel and the carburetor housing to prevent the barrel from
sticking.
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Remove the glow plug and apply a generous amount of after-run oil
into the cylinder head. Reinstall the glow plug and turn the crankshaft
over several times to distribute the oil.
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Once that is done, place the engine in a sealed baggie and remove as
much air from the baggie as possible. Your engine can now be stored for
a long period without worrying about rust or engine degradation.
Resetting the Timing
Engine maintenance should be done on a regular basis to ensure that you
keep the engine running in top form, especially over time. Following these
simple maintenance practices will ensure the long life and dependability
you expect from your engine.
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Avoid running the engine under dusty conditions. If you are in a dusty
environment, we suggest using an air filter over the carburetor.
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At the end of every flying day, purge the engine of fuel by disconnecting
the fuel line from the carburetor and allowing the engine to run dry of fuel.
The timing must be reset if the crankshaft and/or cam gear has been
disassembled. To reset the timing, rotate the crankshaft until the piston is
at top-dead center. (Verify this by looking through the glow plug hole.)
With the piston at top-dead center, install the cam gear with the small
punch mark facing toward you and pointing straight down toward the bottom
of the crankcase. Reinstall the cam gear cover and tighten the screws.
XL 1.80RFS ENGINE MAINTENANCE INFORMATION
ADJUSTING THE VALVES
MAINTENANCE
