816031 Mercury PLUG

Illustration 1 g00684268
Manual Barring Group
(1) Gear
(2) Shaft
(3) Knob
(4) Stem
(5) Slot in shaft (2)
Illustration 2 g00684278
Manual Barring Group
(5) Slot in shaft (2)
(6) Spacer
(7) Guide The manual barring group provides a means of slowly turning the flywheel in order to perform service work on the engine.Note: Prelube the engine as you rotate the crankshaft during the normal maintenance operations. Refer to the Testing And Adjusting Section of this manual.A 3/4 inch hex drive on the end of the shaft (2) is used to turn the gear (1). The guide (7) must be loosened before the shaft is engaged or the shaft is turned.The shaft (2) is spring loaded. The shaft must be pushed toward the flywheel in order to engage the gear (1) in the flywheel ring gear.The shaft can be engaged in position against the flywheel by pushing in on the knob (3). The stem (4) engages in the slotted part (5) of the shaft. When the knob is pushed inward, the O-ring seals shut off the pressure air source (signal to the relay valve) to the starting motor. The loss of air pressure will prevent the start-up of the engine.The barring group can be used to prevent the rotation of the crankshaft. The inside of the spacer (6) is splined. The shaft (2) and the flywheel will be locked in position when the manual barring group is engaged and the guide (7) is tightened to a torque of 270 25 N m (200 18 lb ft).When the manual barring group is not active, this component must be disengaged from the flywheel. Lock this component in position. Tighten the guide (7) to a torque of 270 25 N m (200 18 lb ft).Manual Barring Group (50:1)
Illustration 3 g00322856
Manual Barring Group (50:1 reduction)
(1) Shaft with gear and grease fitting
(2) Locking nut
(3) Knob
(4) Adapter An electric wrench or an air wrench may be used with the manual barring group (50:1 reduction) in order to turn the engine slowly. The manual barring group is used while service work is being performed.Use the following procedure in order to engage the manual barring group:
Loosen locking nut (2).
Pull knob (3) outward while pressing inward on locking nut (2) until the nut is flush with the housing. The nut is part of the pinion shaft which is spring loaded.
Release knob (3) and slowly remove hand pressure from locking nut (2) until the knob engages in the slot of the pinion shaft. Note: If locking nut (2) cannot be flush with the housing, the shaft gear is not meshed with the flywheel ring gear. Maintain inward pressure on the nut while adapter (4) is carefully adjusted. Adjustment of the adapter is achieved by turning the adapter in a