shutoff valve, located between the air intake and the blower, will trip and shut off the air supply to the engine.
Lack of air to the engine will prevent further combustion of the fuel and stop the engine.
The emergency stop knob must be pushed back in after the engine is stopped and the air shutoff valve must be
reset manually. The cause of the malfunction should be determined before the engine is started again.
The tachometer drive shaft is pressed into the end of the camshaft, balance shaft, or governor drive shaft.
When required, a tachometer drive cable adaptor is used to change speed or to change direction of rotation,
depending upon the location of the tachometer drive. A special key is used to connect the drive shaft to the
tachometer drive cable adaptor.
The cable connection at the current tachometer head is a 5/8 inch threaded connection in place of the former
7/8 inch connection. To eliminate possible misalignment, the current tachometer angle drive has a short
flexible cable and incorporates an integral oil seal. The output-shaft key size has been increased from 5/32
inch to SAE 3/16 inch. New flexible drive cables are also required with the current tachometers and angle
Remove Tachometer Drive Shaft
If threads (5/16-24 or 3/8-24) are provided on the outer end of the tachometer drive shaft to accommodate a
removing tool, thread remover J 5901-3, on the shaft. Then attach slide hammer J 23907-1 to the remover. A
few sharp blows of the weight against the slide hammer rod will remove the tachometer drive shaft.
If threads are not provided on the outer end of the tachometer drive shaft, or if the end of the shaft is broken
off, drill and tap the shaft. Then thread a stud into the shaft and remove the shaft with the remover and slide
Use adequate protective measures to prevent the metal particles from falling into
the gear train and oil pan.
When installing a tachometer drive cover assembly or a drive adaptor, it is important they be aligned properly