LET’S TALK GIANT SCALE
increase throttle to about 15% and will allow
the engine to warm up. Once every minute
or two, I increase throttle and adjust the
high-end needle to obtain maximum rpm by
turning the needle clockwise to “lean out”
or counterclockwise to “richen” the engine.
When maximum rpm is obtained, I richen the
setting until it drops about 500rpm to ensure
that the engine will not overheat. It is then
important to adjust the idle disc to result in a
smooth transition from idle to maximum power.
If the engine appears to stutter during the
transition, adjust the idle disc in extremely small
increments. Turn the disc clockwise to eliminate
the poor transition, and turn it counterclockwise
if the engine quits during the transition. Repeat
the process until you are satisfied. For safety
purposes, please make all engine adjustments
after the engine is shut off. Also, settings will
differ with the cowl removed, so patience is a
virtue during this process.
A carburetor on a gasser, like the Zenoah
G- 38 or Desert Aircraft DA-170, is quite similar
to the Moki with respect to the adjustment
procedure. These engines, however, feature a
carburetor that has a high- and a low-speed
needle instead of the high-end needle and idle
disc. You can access the high- and low-end
needles by making two small access holes so
that a long, narrow screwdriver can be used
for fine adjustments. These engines feature
carburetors that have a high- and a low-end
needle marked with an “H” and an “L.” Observe
the full-scale subject and note any possible
access points on the real aircraft that can be
disguised for access to the needles.
For consistent performance—no matter what
type engine, gas or glow—proper cooling
techniques are required; otherwise, the engine
can overheat and a loss of power may occur. If
an engine runs over a given temperature, which
will vary on the engine type, the results can be
fatal for an aircraft. For a Desert Aircraft two-
This screen in front of the engine allows proper airflow over the engine cylinder.
Always observe what was done on the full-scale subject and adapt similar
concepts to the model.
Some models may require a shaft extension or a custom muffler to keep the
engine assembly concealed within the cowl, as it is here on this beautiful
Composite-ARF P- 51 Mustang.
I modified the cooling fins on this Moki 210 to allow the Revolution adapter to
connect properly to the glow plug.
I used a remote glow-plug adapter from Revolution to maintain the scale outline of
the cowl and to keep the glow igniter away from the propeller of the aircraft.