Instruction manual
EN
11
Now that you have the baseline needle valve 
settings, you are ready to start your engine for 
the rst time. With the 15GX it is very  
important to allow the temperature to 
stabilize above 170°F (75°C) before making 
any adjustments; adjusting prior to the engine 
warming up will lead you to inaccurate 
settings. As the engine warms up you will 
notice the rpms naturally rising.
If you do not have a temp gun or have sensors 
installed on your engine, allow the engine to 
run at half throttle for at least 45 seconds be-
fore attempting to set the high-speed needle. 
If you have accurately set the low-speed 
needle as described you should not need to 
adjust it.
Priming
1.  Make sure your ignition is off. 
2. Open the throttle fully and, either by hold-
ing a finger over the carburetor intake or 
the mufer exhaust, ip the propeller 6 
times.
3. Remove your nger from either the carbure-
tor or muffler exhaust and flip the engine 
another 6 times.
4. Close the carburetor completely with your 
throttle stick and then open it two detents 
from closed. This will allow the engine to 
start at a high throttle setting.
Because each fuel system and installation 
is slightly different, you may find the need 
to modify the above procedure for your 
individual setup. The above procedure should 
work for most installations.
Starting and Operating the 15GX Engine
Telemetry is a huge asset to help you tune 
your engine. The ignition module is even 
capable of communicating with Spektrum 
telemetry systems directly so you won’t have 
to add an additional RPM sensor. You will 
need to connect the Evolution Ignition 
Telemetry Adapter (EVOA107) between the 
RPM port on the ignition unit and the RPM 
port on your Spektrum telemetry module in 
order to utilize this feature. Telemetry systems 
other than Spektrum may require a dedicated 
RPM sensor. 
We recommend using the Spektrum DSMX Full 
Range Aircraft Telemetry Module (SPM9548) 
in conjunction with the included adapter. This 
system allows you to see real-time RPM and 
temperature readings from the engine.
The temperature sensor should be wrapped 
around the base of the spark plug on the 
cylinder head. Using telemetry gives you an 
accurate representation of actual temperature 
and rpm figures during use, and warnings 
can be set to go off if your engine is getting 
too hot.
The temperature range can be 275–300ºF 
on average. Set your maximum temperature 
warning to go off if the engine exceeds 350ºF. 
If your engine is continually near this peak 
temperature or higher, immediately decrease 
throttle to bring the temperature down. If this 
continues to occur, land the airplane and add 
additional baffling to your cowl. It is not good 
for the engine to run at temperatures this high 
and could cause damage if not attended to.
Telemetry
Until the engine is broken in, use an electric 
starter to start the engine. Once it is fully 
broken in it can be started by hand, but it is 
easier and safer to start the engine with an 
electric starter.
1.  Turn on the ignition.
2. Rotate the propeller in a backwards direc-
tion against compression.
3. Push the starter rmly against the nose 
cone and engage. The engine should start 
relatively quickly, within 1–2 seconds. Once 
the engine starts disengage the starter.
4. Let the engine run at mid-throttle for 45 
seconds to stabilize the temperatures.
  a. If the engine doesn’t start quickly, disen-
gage the starter. Continuously running 
the starter can flood the engine.
b. Check to make that fuel is moving 
through the carburetor system.
c.  If the engine appears not to have any 
fuel, repeat the priming procedure 
above.
d. Repeat 1–4 of Starting and Running the 
Engine.
Starting and Running the Engine










