Tachometer Indicator; Troubleshooting Tachometer - Piper Dakota Maintenance Manual

TACHOMETER INDICATOR

The tachometer is connected to the engine accessory by a flexible cable and provides an indication of
crankshaft speed in revolutions per minute. The instrument has a recording mechanism for recording time that
engine is in actual operation.
TROUBLE
No reading on indicator,
either permanent or in-
termittent.
Pointer oscillates ex-
cessively.
Indicator changes in climb.
Pointer goes all the way to
stop, more noticeable in
cold weather.
Pointer jumps at idle.
Tachometer cable breaks.
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
CHART 7702. TROUBLESHOOTING (TACHOMETER)
Broken shaft.
Loose cable connections.
Rough spot on, or sharp
bend in shaft.
Excessive friction in
instrument.
Excessive clearance in
speed cup.
Excessive lubricant in in-
struments.
Speed cup hitting rotating
magnet.
Cable bent too sharply.
CAUSE
2K5
REMEDY
Replace instrument.
Tighten cable.
Repair or replace.
Replace instrument.
Replace instrument.
Replace instrument.
Replace instrument.
Reroute cable.
77 - 12 - 00
Page 77 - 02
Reissued: August 1, 1986