User Manual
26
Check  these  conditions  and,  instead  of 
pressing the starter button after applying 
the starter, have the starter spinning before 
applying  it  to  the  engine,  to  give  it  a 
"running start".
When the engine starts, slowly open the 
throttle,  leaving  the  needle-valve  at  its  rich 
starting  setting  to  promote  cool  running 
conditions. However, if the engine slows 
down because the mixture is excessively 
rich, the needle-valve may be closed a little 
to speed it up until it runs evenly.
7.
8.
Note:
Make sure that the throttle linkage is made 
so that the throttle is fully closed when the 
throttle  lever as  well  as  trim  lever on  the 
transmitter are fully pulled down.
How to stop the engine
Pull  down  the  throttle  lever  and  trim  lever  on 
the transmitter fully.
Electric starter
Make sure that the
direction or rotation
is correct.
Now disconnect current to the glowplug and 
gradually close the needle-valve so that the 
rpm increases. 
Make adjustments to the needle in small 
steps. 
Abrupt  changes  at this  stage are  likely  to 
cause the engine to stall. Restart the engine 
by  simply  applying  the  starter  with  the 
glowplug re-energized and the throttle at its 
starting setting.
27
RUNNING-IN ("Breaking-in")
The recommended procedure is as follows:
Use  the  same  fuel  and  prop  as  you  intend 
for flying your model.
1.
2.
Open  the  needle-valve  3-3.5 turns  from  the 
fully closed position and start the engine.
3.
Open  the throttle  slowly  to the  mid speed 
position,  and  disconnect  the  current  to  the 
glowplug.
4.
Now open the throttle  slowly to the fully 
opened  position  and  run  the  engine  for  no 
more  than  5  seconds  with  the  needle-valve 
tuned to produced near maximum r.p.m., 
then, immediately, slow the engine down 
again  by  opening  the  needle-valve 
approximately one turn. The rich mixture, so 
induced,  will  cool  the  engine,  at  the  same 
time providing increased lubrication.
All internal-combustion engines benefit from 
extra  care  when  they  are  run  for  the  first  few 
timesknown  as  running-in  or  breaking-in.  This 
allows  the  working  parts  to  mate  together 
under  load  at  operating  temperature. 
Therefore, it is vitally important to complete the 
break-in  before  allowing  the  engine  to  run 
continuously  at  high  speed  and  before 
finalizing  carburetor  adjustments.  However, 
because  O.S.  engines  are  produced  with  the 
aid  of  the  finest  modern  precision  machinery 
and from the best and most suitable materials, 
only a short and simple running-in procedure is 
called  for  and  can  be  carried  out with  the 
engine installed in the model. 
5.
Repeat this process, alternately running the 
engine  fast  and  slow  by  means  of  the 
needle-valve, while keeping the throttle fully 
open, then begin to extend the short periods 
of high-speed  operation until two  tanks of 
fuel have been consumed.










