Rotax OM-912, Operator'S Manual

Page: 49 / 64

Effectivity: 912 Serie BRP-Rotax page 10 - 19
OM Edition 1 / Rev. 0 Jan. 01/2007
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- Preheat engine using hot air.
Beyond that observe following advices for operation at extremely
low temperatures:
◆
NOTE: Distinguish between two kinds of carb icing:
1) Icing due to water in fuel
2) Icing because of high air humidity
Addendum to note 1)
Water in fuel will accumulate at the lower parts of the fuel system
and leads to freezing of fuel lines, filters or jets.
Remedy:
- Use non-contaminated fuel (filtered through suède)
- Generously sized water separators
- Fuel lines routing inclined
- Prevent condensation of humidity, i.e. avoid temperature diffe-
rences between aircraft and fuel.
▲
WARNING: Fuels containing alcohol always carry a small
amount of water in solution. In case of temper-
ature changes or increase of alcohol content,
water or a mixture of alcohol and water may set-
tle and could cause troubles.
Addendum to note 2)
Carburetor icing due to humidity may occur on the venturi and on
the throttle valve due to fuel evaporation and leads to performance
loss and change in mixture. Intake air pre-heating is the only effec-
tive remedy.