Rotax CESSNA 150 Manual page 49

Airplane Flight
Manual Cessna F150L
Nr. 160
Converted with kit 4-9
NS402S with ROTAX 912 S3 and Page:
HOFFMANN HO-V352F/170FQ+10 Revision 1
CHECKING THE IGNITION MODULES
Checking the ignition modules should be done at an engine speed of 1700 rpm, prop control
on high setting (forward). Set the ignition switch first to "R" position and notice the rpm
droppage. then return the switch to "BOTH" position to clear the set of spark plugs. Then move
switch to „L" position note the rpm and return the switch to „BOTH" position. Rpm drop should
not exceed 135 rpm on either module or show greater than 50 rpm difference between
modules.. If there is a doubt concerning operation of the ignition system, rpm checks at higher
engine speeds will usually confirm whether a deficiency exists
An absence of rpm drop may be an indication of faulty grounding of the one side of the ignition
system or should be cause for suspicion that the ignition module timing is too early.
CHEKING THE GENERATORS
For flights where electrical power is essential (night or IFR flights) A generator and voltage
regulator check can be done by turning on the landing light for short period (3 to 5 seconds) (if
installed) or by lowering the landing flaps when engine on idle. The ammeter should remain
within needle width of the zero when voltage regulators and generators are working properly
TAKE OFF
ENGINE POWER CHECK
It is important to check full-throttle engine operation early in the take-off run. Any sign of rough
engine operation or sluggish engine acceleration is good cause for discontinue the take-off. If
this occurs, you are justified in making a thorough full throttle static runup before another take-
off attempted the engine should run smoothly and turn 2280 - 2320 rpm with carburetor heat
off
Full throttle runups over loose gravel are especially harmful to propeller tips. When take-offs
must be made over a gravel surface, it is very important that the throttle be advanced slowly.
This allows the airplane to start rolling before high rpm is developed, and the gravel will be
blown back of the propeller rather than pulled int.it. If unavoidable small bumps on the
propeller blades are detected, they should be removed immediately, as described in Section
VI.
After full throttle is applied, adjust the throttle friction lock clockwise to prevent the throttle from
creeping back from a maximum power position. Similar friction lock adjustment should be
made as required in other flight conditions to maintain a fixed throttle setting