Warning : The greatest threat for the engine is when it is working on too
lean mixture. This leads to rapid temperature growth of the piston crown, and
could result in melting or burning of the piston crown. In such case, serious
damages of cylinder, piston and crankshaft bearing could appear. In practice, it
means very high repair costs. Due to the fact that only the user is responsible
for mixture composition, the producer takes no responsibility for damages
caused by overloading the engine thermally, engine seizure, tearing off the
connecting rod, jamming the piston rings, using inadequate oil, or using not
enough amount of oil!
The run-in during the flight is divided into two stages:
First stage involves making first take-offs and first flights maintaining the lowest possible
speed. Maximum speed must not be reached unless it is absolutely necessary and it should
take as short as possible. High altitudes are not advisable, but if necessary they should be
reached in steps, making pauses while ascending in order to cool the engine. We advise you
to maintain high ascent for no longer than half a minute, then keep lower ascent for about
one minute.
The first test flight should take no longer than 10-20 minutes. After landing you
should check combustion conditions by checking the condition of the spark plug.
Spark plug evaluation in the engine working previously for a long time at idle speed is
not reliable. For proper evaluation you should turn the engine off after a few minutes on
medium and high speed (horizontal flight) and land on the turned-off engine.
Second stage: If the spark plug has dark color or is black after the test flight, we can
continue flying also using maximum engine power.
Attention : There are only two ways of checking whether the mixture’s
composition is correct! First, taking the temperature of the fumes. Second,
evaluating the state of the spark plug!
2016-06-22
