20
MAINTENANCE SECTION
8. Using an induction coil or oven, heat the Motor
Housing until the motor opening is large enough to be
placed over the Cylinder. At that time, install the
Housing over the Cylinder and Front End Plate
making sure the radial End Plate Alignment Pin (23)
in the Rear End Plate enters the notch in the Motor
Housing.
Take all precautions necessary to prevent being
burned by handling warm or hot parts.
9. Allow the assembly to cool and install the Motor Case
Cover Gasket (33) and Motor Case Cover (31).
10. Secure the Cover to the Housing by installing the four
Motor Case Cover Screws (34) and Lock Washers
(35). Tighten each Screw between 45 and 50 in–lb
(5.1 and 5.6 Nm) torque.
11. Install the Exhaust Deflector (21) in the bottom of the
handle of the Motor Housing (1) and tighten it
between 20 and 25 ft–lb (27 and 34 Nm) torque.
12. Thread the Inlet Bushing (20) into the bottom of the
handle of the Motor Housing and tighten it between
30 and 35 ft–lb (40 and 47 Nm) torque.
13. Install the Throttle Rod Seal (16) in the groove on the
large hub of the Throttle Rod (15).
14. Install the Throttle Valve Seal (13) in the groove on
the large hub of the Throttle Valve (12).
15. Slide the Throttle Valve, Valve Seal end first, onto the
Throttle Valve Rod.
16. Secure the Throttle Valve Assembly by installing the
Valve Retaining Ring (14) in the small groove on the
Throttle Valve Rod.
17. Install the three Throttle Bushing Seals (11) in the
grooves on the Throttle Bushing (10).
18. Slide the Throttle Bushing Assembly onto the shaft of
the Throttle Valve Rod and position the Trigger (17)
on the same shaft. Install the Trigger Pin (18).
19. Insert the assembled Trigger into the Housing. Make
certain the widest end of the Trigger is nearest the
motor bore and the narrowest portion of the Throttle
Valve aligns with hole for the Throttle Retaining Pin
(19). Install the Pin making certain it captures the
Throttle Valve and secures the assembled Trigger.
20. Align the detent hole in the Reverse Valve (5) with
the hole inside the Reverse Valve Bushing (4) and
slide the Valve into the Bushing until almost reaching
the detent hole. Insert the Reverse Valve Detent
Spring (7) and Reverse Valve Detent Ball (6) into the
hole and while compressing the Spring with the Ball,
slide the Valve completely into the Bushing.
21. Using snap ring pliers, install the Reverse Valve
Retainer (8).
22. Slide the Reverse Lever (2) onto the Reverse Valve,
making certain the cast lug enters the notch on the
face of the Reverse Valve Bushing. Secure the Lever
to the Valve by inserting the Reverse Lever Retaining
Pin (3).
Assembly of the Impulse Mechanism
1. Insert the long shaft of the Piston Stop (69) into the
central opening of the O–ring Installer furnished with
the Tool Kit (Part No. 1900P–99). Place the Piston
Stop Seal (70) on the tapered end of the Installer and
roll the Seal up the taper and into the groove on the
large body of the Piston Stop. Repeat the procedure
with the other Piston Stop and Seal.
2. When looking inside the central opening of the Liner
Assembly (66), the internal wall has three holes on
one side which do not extend through the wall. The
opening on the end face of that wall is for the Torque
Valve Piston (68). Install the Torque Valve Piston,
large end trailing, into that opening.
3. Insert the Piston Stop Assist Spring (71) into the hole
in the end face of the opposite wall.
4. Thread the Threaded Tee Wrench furnished with the
Tool Kit into one of the Piston Stop Assemblies and
using the Wrench to hold the Assembly, insert the
Assembly into the opening against Piston. Mark this
opening with a felt marker to indicate that it contains
the Torque Valve Piston.
5. Unscrew the Wrench and in the same manner, install
the other Piston Stop Assembly in the hole with the
Spring.
6. Install the Rear Liner Cover Seal (72) in the annular
groove on the face of the Rear Liner Cover (73).
7. Install the two Front Liner Cover Piston Seals (59) in
the openings on the face of the Front Liner Cover
(50).
8. Install the Seal Back–Up Ring (58) followed by the
Drive Shaft O–ring (57) in the central opening in the
face of the Front Liner Cover.
9. Insert the short round hub of the Drive Shaft (61) into
the central opening of the Rear Liner Cover.
10. Insert a Blade (64) into one slot in the Drive Shaft.
Install the Blade Springs (65) through the Drive Shaft
and into the holes in the Blade. Place the remaining
Blade on the Springs making certain the Springs enter
the holes in that Blade.
11. Using finger pressure, compress the Springs with the
Blades until the outer edges of the Blades are flush
with the drive shaft surface. Capture the Blades in
thisposition by installing the Liner Assembly, piston
stop end trailing, over the Drive Shaft and against the
Rear Liner Cover.
