Magnum XL .30RFS Operating Instructions Manual - page 2
PROPELLER, FUEL & GLOW PLUG
q Propeller Recommendation
The diameter and pitch of the propeller needed for the XL .30RFS will
vary greatly depending on the application the engine is used in. The weight,
drag and the type of model and how you intend to fly it are all factors in
determining the correct size of propeller to use. Experimentation will be
necessary to find the optimal size propeller for your particular application.
Ideally you want to use a propeller that the engine will turn in the 9,000 -
12,000 R.P.M. range on the ground, yet power the airplane sufficiently.
Using a propeller that is too small will cause the engine to run at too high
an R.P.M. Using a propeller that is too large will cause the engine run at
too low an R.P.M. and cause the engine to lug down too much. In both
instances this will lead to difficulty in making needle valve adjustments,
premature engine wear and eventual engine failure.
Propeller Size Recommendations
q Engine Bolts and Firewall Requirements
The XL .30RFS engine should be mounted to a glass filled motor mount
(Hayes Products Part # 011 recommended) or to an integrated wood beam
mount built into the fuselage structure of the aircraft. Use only high
quality # 4 sheet metal screws and washers to mount the engine to a
glass filled mount. Use 4-40 socket cap screws, washers and locknuts to
mount the engine to a wood beam mount. If using a glass filled mount,
the firewall in the airplane should be aircraft grade plywood no less than
3/16” thick. The firewall should also be reinforced to meet the torque
and power of the engine.
q Muffler and Exhaust Pipe Installation
The muffler threads into the exhaust pipe, which then threads into the side
of the cylinder head. Both assemblies are held in place using two nuts.
First, thread one nut onto the muffler. Thread the muffler into the exhaust
pipe. The muffler should be threaded in no less than 1/4” to prevent vibra-
tion from damaging the threads.
Once you have threaded the muf-
fler into the exhaust pipe use an
open end wrench and tighten the nut
up against the exhaust pipe. This
will prevent the muffler from loos-
ening. The exhaust pipe is adjust-
able to better match the scale ap-
pearance and installation of your
particular application. Thread the second nut onto the exhaust pipe. Thread
the exhaust pipe into the cylinder head. The pipe should be threaded in no
less than 1/4” to prevent vibration from damaging the threads. Once you
have threaded the exhaust pipe in place and into the proper position for
your application, use an open end wrench and tighten the nut against the
cylinder head. This will prevent the exhaust pipe from loosening.
q Fuel Tank Size and Orientation to Carburetor
Ideally the stopper in the fuel tank should be even with the high speed
needle valve or just slightly below the high speed needle valve. Most
models will only allow the fuel tank to be mounted higher than the ideal
location. A fuel tank that is positioned higher than the ideal location usu-
ally doesn’t pose any problem except when it is mounted excessively higher
and/or used in conjunction with an inverted mounted engine or during ex-
treme aerobatic flight. If mounting your engine inverted it is advised to
lower the fuel tank so the stopper is slightly below the high speed needle
valve. Doing this will prevent fuel from siphoning into the engine and
flooding it when the fuel tank is full. If you cannot lower the fuel tank far
enough, we suggest lowering it as far as can be allowed in your particular
application.
The size of the fuel tank used should be 6oz. - 8oz. depending on the
model and the length of flights desired. Use of a 8oz. tank will provide
between 15 - 20 minutes of run time at full throttle. Use of a fuel tank any
larger than 8oz. can lead to excessive leaning of the engine during flight
and is not recommended.
q Rotor Bolt
The rotor bolt holds the throttle barrel into the carburetor body and does
not need adjustment. It also pre-
vents the throttle barrel from being
over-rotated in either direction. To
adjust the idle setting, use the trim
lever on your transmitter. The trim
lever should be set so that when the
lever is fully forward, the engine
will ilde reliably. When you pull
back the trim lever all the way the
throttle barrel should close completely to shut off the engine.
q Needle Valve Extension
If an extension is required to adjust the high speed needle valve, use a
Use a 9 x 5 propeller for the break-in procedure
9 x 5
9 x 8
10 x 6
9 x 6
10 x 4
11 x 3
9 x 7
10 x 5
11 x 4
1.5mm diameter wire of the necessary length. Loosen the set screw in
the side of the needle valve, insert the wire into the end of the needle
valve and tighten the set screw firmly. If the extension is more than 3”
long we recommend supporting the outer end of the extension to prevent
excessive vibration.
q Propeller Installation
Note: Before installing any propeller it must be properly balanced.
Running an engine using an improperly balanced propeller can lead to
excessive vibration which will cause excessive stress and wear on both the
engine and the airframe. Overall performance will also be reduced. Bal-
ance the propeller using the recommended method stated by the propeller
manufacturer. Several products are available to properly balance propel-
lers. Ask your local retailer for more information about these items.
Using a 1/4” drill bit or a prop reamer, drill out the hole in the propeller
hub to fit the crankshaft. The crank-
shaft is 1/4” in diameter. Slide the
propeller onto the crankshaft, up
against the drive washer. Slide the
propeller washer up against the pro-
peller. Thread the prop nut onto the
crankshaft. Tighten the prop nut
completely to secure the propeller
in place. Use the proper size open
end wrench or adjustable wrench. Do not use pliers.
Note: If you are installing a spinner onto your engine the cone of the
spinner must not rub against the propeller. If the spinner cone rubs against
the propeller this could lead to propeller damage and eventual propeller
failure.
q Glow Plug Recommendation
Glow plugs can make a big difference in how your engine performs. For
the XL .30RFS we recommend using a “hot” type of glow plug intended
specifically for four cycle engines. Do not use “cold” glow plugs or those
intended for two cycle engines. Using the wrong type of glow plug will
cause the engine to run erratic and make it difficult to tune properly.
Exhaust
Pipe
Nut
Nut
Rotor
Bolt
Nut
Prop Nut
Prop Washer