Jabiru J450 Constructors Manual
Post-Paint>Fuselage>Install electrical wiring
Tuesday, April 6, 2010
227 of 343
Fit the tacho sender unit
For this step you will need to rotate the
engine, which may cause 1 or 2 of the sealing
plugs to pop off of the exhaust pipes and
possibly some preserving oil may drip out, so
place some rag under the engine until this
step is complete. You will require a lever to
turn the engine – in our factory we use a tool
that fits onto the propeller flange.
Rotate the engine until a tacho timing tag can
be seen under the tacho sender mount (the
threaded fitting at the left rear of the engine)
- refer to the photo at right for detail.
Remove one lock nut from the sender unit
and screw it into the fitting, then carefully
screw it down until it
just
touches the timing
tag. Unscrew the sender unit one full turn and
tighten the lock nut finger tight.
Now rotate the engine one half of a turn until the other timing tag is under the sender unit and
screw the sender down until it
just
touches that tag, which should be one full turn. Back the
sender unit out one half of one turn and firmly but carefully tighten the locking nut.
Wire the magnetos
Feed a plain length of 16 gauge wire through the hole in the side of each magneto, strip 4mm
of insulation off and crimp a red female spade connector to the wire with a black heat shrink
tag. A black tag is used because the magneto wire is used to earth the magneto to turn it off.
Fit the CHT (Cylinder Head Temperature) plug and wiring
Zip tie the CHT connecting plug to the front of the left hand top engine mount with the high
temperature wire facing back. The sensor will be fitted to the left rear spark plug later in this
task. The main photo on the next page shows the CHT connecting plug fitted.
Tacho sender
mount
Tacho timing
tag (on the
flywheel)
Front of
engine
Right magneto
Left magneto