User Manual

engine. In all cases, the firewall / airframe mounting surface must be absolutely flat or
potentially damaging forces can be exerted to the engine or mounting hardware which can
cause failure.
Check to see that the carburetor has adequate clearance (at least 1in.) to anything for
proper breathing. If it doesn’t, make appropriate adjustments. Make sure that your
airplanes fuel tank and lines are made for gasoline use, that the tank is adequately vented
and that the feed line clunk can move freely in all directions and not get hung up anywhere.
We recommend using a filter between your gas supply and airplane fuel tank. If you use a
fuel filter between the airplane tank and the carburetor, make sure it is of adequate size to
supply an unobstructed flow of fuel to the carburetor the engine may not run correctly.
Make sure that the cowl openings on your plane provide enough airflow for proper cooling.
Ideally, all of the cooling fins of the cylinder should be exposed directly to unobstructed
flow of cooling air and there should be 3 times as much air exit area as intake area. Many
planes have cowl openings that actual y inhibit proper cooling of single cylinder engines.
Their openings were made to give a scale appearance of the full size planes they are
patterned after. Along with the openings described above, blocking the scale openings
either partially or wholly can significantly help promote cooling airflow over the cylinder
fins.
Many types of fuelling devices (fuel dots, filler valves, etc.) are available for your use. Our
experience has shown that often the simplest is the best. Regardless of which device you
decide to use, be very wary of air leaks, as they can be detrimental to the proper operation
of your engine.
NOTE: Always use Loctite on engine mounting hardware and make sure your models
firewall and engine box are adequately reinforced (pinned, soaked in thin CA, etc.).
Engine Break In
Break in running should be done with regular 90 octane gas mixed with a high quality
petroleum based 2 cycle oil at a ratio of 30:1. The engine should be run installed in the
airframe with wings attached, on the ground for at leat 20 minutes at 2500rpm. Ground
running should be done with a slightly smaller prop and with the cowl off to promote good
cooling. It is not recommended that you run the engine in a test stand, as they do not allow
vibration energy to be properly dissipated. Plus, it is not needed. Your engine is ready to
go.
During the break-in process (a couple of gallons of gas) the carburetor may need to be
adjusted and the engine should be flown at light load and varying speed for enough time
to have the oil/gas run through it.
After you have run a couple of gallons of fuel through, you can switch to a full synthetic 2
cycle oil mixed at a ratio of 50:1. Note that when you switch to synthetic 2-cycle oil, it is
likely that the carburetor mixture and idle speed will need to be adjusted.
We recommend high quality synthetic 2 cycle oil. Never use outboard motor 2 cycle oil.
Carburetor Adjustments
Every engine has been adjusted to average mixture settings, which will most likely allow
the engine to start and run in most locations.
However, as altitudes and barometric pressures vary by location and even by day, it is