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IMPORTANT
Your XLS series engine is an ABC engine. The cylinder
sleeve is tapered at the top, causing severe resistance when the piston
moves through the top of the stroke. This is normal. When the engine
heats up to operating temperature, this resistance will decrease and the
proper clearance will be achieved. The break-in procedure will guide you
through the steps necessary to properly break in your new ABC engine.
Please follow the steps in this section closely.
The break-in process allows the engine parts to perfectly fit each other and
properly protect each part from premature wear. The engine should be
broken in using a fuel that contains no more than 10% nitro methane and
no less than 18% Castor/synthetic blend lubricant.
Fuel containing only
synthetic lubricants should not be used during the break-in procedure.
For the break-in procedure we recommend mounting the engine into the
airplane it will be used in. This way the muffler, fuel tank and throttle linkage
can all be tested in combination with the engine. If your airplane uses a
cowling, it should be removed during the break-in procedure.
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1) Turn the high speed needle valve out 2-1/2 turns from the fully closed
position.
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2) If you are using an electric starter to start the engine, follow the procedure
in the previous section. If you are starting the engine by hand, follow that
procedure in the previous section.
❑
3) Open the throttle barrel to approximately 1/4 throttle. Connect the
power to the glow plug. Start the engine using an electric starter or by hand.
If starting by hand you will need to vigorously flip the propeller through the
compression stroke several times before the engine will start.
❑
4) Once the engine starts, open the throttle barrel to about 1/2 throttle.
You may need to lean the high speed needle valve in about 1/4 turn to keep
the engine running at half throttle.
❑
5) After the engine has been running about 1 minute, remove the power
from the glow plug and slowly advance the throttle barrel to full throttle.
Adjust the high speed needle valve so that the engine is running very rich.
You should notice excessive white smoke coming from the exhaust. Let the
engine run for approximately 10 minutes then stop the engine.
❑
6) Let the engine cool for approximately 10 minutes then restart it. Set
the high speed needle valve mixture to a slightly leaner setting, about 1/4
turn more in. Let the engine run for about 5 minutes at this setting, then
stop the engine and let it cool for approximately 10 minutes.
❑
7) Repeat the procedure in step # 6, while leaning the needle valve
slightly more each time. In all, you should run the engine about a total of 45
minutes of actual running time. After 45 minutes of run-time the engine is
ready for flight. Fly the airplane with the engine set as rich as possible, but
with adequate power to fly the airplane. After each flight, lean the mixture
slightly. Continue to do this for about 5 flights. At this point the engine should
hold a good setting on the high speed needle valve and you can begin to
fine tune the needle valve settings to increase performance.
Now that your engine is broken in, you can set the high and low speed needle
valves for optimum performance.
WARNING
Be careful never to lean the engine out too much. Remember
that the lubricants for your engine are suspended in the fuel. If you lean
out the fuel mixture too much you will also be lowering the amount of
lubricant entering your engine. Less lubricant means more chance of
your engine overheating and possible engine failure.
Information about returning your engine for warranty service, can be
found on the separate sheets packaged with these Operating Instructions.
Magnum XLS series engines are distributed exclusively by Global Hobby Distributors
18480 Bandilier Circle, Fountain Valley, CA 92708
All contents copyright © 2006, Global Hobby Distributors
Revision 1 September 2006
BREAK-IN PROCEDURE
OPTIMIZING THE MIXTURE SETTINGS
Setting the High Speed Needle Valve
❑
1) Start the engine and remove the power from the glow plug. Allow the
engine to warm up for about 30 seconds.
❑
2) After the engine has warmed up, slowly lean the high speed mixture
until the engine reaches peak rpm. After reaching peak rpm, richen the
mixture slightly until an audible drop in rpm is heard. If you are using a
tachometer this should be between a 200 - 300 rpm drop.
❑
3) With the engine running at full power, carefully lift the nose of the
airplane about 45º into the air. The mixture should not become too lean,
but you may hear a slight increase in rpm. If the engine sags, or loses rpm
when you hold the nose up, the mixture is too lean. If this is the case, slightly
richen the mixture and follow the test once more.
IMPORTANT
Rpm will increase about 10% - 30% in the air. This is
due to the forward motion of the aircraft as it is flying. Because of this,
more air is entering the carburetor, at a higher force, which causes the
mixture to lean out. Additionally, as the fuel level in the fuel tank goes
down, fuel draw becomes more difficult for the engine, especially during
aerobatics, thus causing the mixture to go lean. It is imperative that you
set the mixture rich while on the ground to compensate for the leaning
tendencies that will happen in the air. Always watch the exhaust during
your flight. The engine should leave a noticeable white smoke trail at
all times. If there is no smoke trail, the engine is running too lean. You
should land immediately and reset the mixture.
Setting the Low Speed Needle Valve
❑
1) Start the engine and lean out the high speed needle valve as per the
previous steps. Close the throttle until the slowest
reliable
idle is reached.
Allow the engine to idle for about 15 - 20 seconds.
❑
2) Quickly advance the throttle to full. If the engine just stops running
as soon as the throttle is advanced, the idle mixture is too lean. With the
engine stopped, richen the idle mixture about 1/8 of a turn.
❑
3) Repeat steps # 1 and # 2 until the engine will transition from idle to
full throttle smoothly. Minor hesitation in the transition is normal.
❑
4) If you quickly advance the throttle from idle to full and the engine seems
to be very rich during transition (i.e., lots of smoke coming from the exhaust),
the mixture is too rich. With the engine stopped, lean the idle mixture about
1/8 of a turn.
❑
5) Repeat steps # 1 and # 4 until the engine will transition from idle to
full throttle smoothly. Minor hesitation in the transition is normal.
●
Avoid running the engine under dusty conditions. If you are in a dusty
environment we suggest using an air filter over the carburetor.
●
At the end of every flying day, purge the engine of fuel by disconnecting
the fuel line and allowing the engine to run dry of fuel.
●
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. Rotate the crankshaft several times to distribute
the oil throughout the engine. This will prevent the engine from forming rust.
●
Periodically check to make sure all of the engine bolts are tight.
ENGINE MAINTENANCE