The Light Weight Engine Houtekietstraat 11
B-8540 Deerlijk, Belgium
EFFECTIVITY
page 26
ALL
19-3-2019
NOTE
A damaged sealing surface of the filler cap or a damaged head seal for example, cannot be recognized
by checking the level of the cooling liquid in the overflow reservoir. It is possible that when the motor
gets warm, the cooling liquid is pushed into the reservoir, but as the engine cools the liquid is not sucked
back in the cooling system of the engine anymore. An indication of this is, for example, if the
temperature of the motor is normal during the flight, but during or after the landing the temperature
of the engine does not get down, or even gets higher.
For full inspection of the cooling system the upper part of the cowling has to be removed. All parts
and pipes of the cooling system should then be checked visually for leakage, damage or signs of
abrasion. Check the hose clips of the pipes for tightness, open the cap of the header tank (only if engine
is cold) and verify if the header tank is full of coolant (level should be just below the sealing surface).
Check if the sealing surfaces of the header tank and of the cap are clean and without visible damage.
If not change the damaged parts and refill the cooling liquid if required before undertaking any flight.
Some Microlight/Ultralight aircraft are equipped with an oil water heat exchanger. In the heat
exchanger the oil exchanges its heat with the cooling liquid. This means that the cold oil is heated and
the hot oil cooled down by the cooling liquid. Once the engine is heated up to normal range and while
it is operated normally (horizontal flight) the temperature of the oil and of the cooling liquid are tightly
related to each other, whereat the temperature of the oil should be 10°C to 15°C (50 to 59 f) higher
than the cooling liquid.
NOTE
For example: Oil temperature is 90°C to 95°C (194 to 203 F) and cooling liquid has about 80°C. (176 f
Should the difference of the temperature be higher or lower, the oil, the cooling liquid and the sensors
needs to be checked.
Oil Supply
The oil supply is provided by the oil pump and the dry sump system.
CAUTION!
(1)
use only oil specified in this manual
(2)
don’t use any additives
.
