Bailey Moyes 912 Dragonfly, Maintenance Manual

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If desired, a combination page can be programmed to display the tachometer reading being sensed by
the tachometer input #2. This is accomplished by selecting "N2" to be displayed on a combination
page. N2 will always show the RPM calculated from tachometer input #2. The normal "Tach" display
will show EITHER tachometer input #1 if it is available, OR tachometer input #2 if it is available.
6.2.2 Testing Tachometer Accuracy
A simple test to help verify the RPM readings are accurate can be made by running the engine at night,
and looking through the propeller at a florescent or mercury vapor light. The pulsation of the light will
make the propeller to appear to stopped at various RPMs. Verify the propeller appears stopped at the
RPMs shown in the following table. Note that this applies to lights powered by 60 Hz electrical power,
such as that used in the United States and Canada. Also remember that this is the propeller RPM, and
the engine RPM will by higher by the reduction ratio if the engine includes a propeller speed reduction
unit.
2-Blade Propeller 3-Blade Propeller
600 240
720 300
1200 480
1440 600
1800 1200
3600 2400
CAUTION : If there is ANY DOUBT that the tachometer is working correctly, use another
tachometer that is known good to verify the EIS is giving the correct tachometer reading. Attempting a
take-off with an inaccurate tachometer could result in less than full power being available, and this
could be very dangerous.
6.3 Other Checks
CAUTION : Verify that no leaks are observed around the coolant temperature sensor (if so equipped),
as well as the oil pressure and temperature sensors. Loss of engine oil or coolant will severely damage
your engine, and will result in sudden stoppage.
The remainder of the functions should now be checked out by observing the measurements displayed
by the EIS. Any measurements that appear unreasonable should be checked to verify their accuracy.
Your EIS is now ready to use. Please refer to the “Before Each Flight” section.
7.
Configuring the EIS for your airplane.
Configuring the EIS for your airplane simply involves setting various entries in the “Configuration
Set” pages. These settings tell the instrument details about your engine (such as how many pulses per
revolution for the tachometer, units, etc.), how the auxiliary inputs are used, the desired units, etc. The
best way to set these items is to work your way through the list describing these settings below.
To access the “Configuration Set” pages, press and hold the center and right button until the screen
shows “UP DOWN NEXT” on the bottom row. The display will momentarily show the “Set Lean
Pt” page while holding these buttons. This is normal. After about 5-10 seconds, the “Configuration
Set” pages will be displayed. This deliberate action is required so that anyone unfamiliar with the
instrument will not inadvertently alter the configuration of your instrument.