Remove/install constant-speed throttle

AR01.50-W-1000A

Remove/install constant-speed throttle

19.9.06

 

Remove/install

1

Remove cylinder head

Model 374, 375, 673, 674, 676, 950, 952, 953, 954, 957, 958, 970, 972, 974, 975, 976

AR01.30-W-5800A

Models 668, 670

AR01.30-D-5800D

2

Remove nozzle holder combinations

Engine 904.9 up to engine end no. 040487

AR07.03-W-6831A

Engine 904.9 from engine end no. 040488,

Engine 906.9

AR07.03-W-6831C

3

Remove cap (1) on cylinder head

 Installation: Replace O-ring (2).

4

Insert a suitable spacer (11) between valve disk and base

 Height of spacer (11) about 5.3 mm.

5

Use pliers (12) to remove piston (4)

 Installation: Check sealing ring (3) on piston (4); replace piston (4) and sealing ring (3) if necessary.

Lubricate piston (4) and sealing ring (3).



*442589003700

6

Remove collets (5)

 Compress spring (7) with spring disk compressor (13) and take out collets (5) with magnetic pin (15).

 Installation: Collets (5) must latch.



*210589004000



*442589056300

7

Relieve pressure on spring (7), take out top spring retainer (6), spring (7) and bottom spring retainer (8)

 Installation: Fit bottom spring plate (8), spring (7) and top spring plate (6) onto stem of constant throttle valve (9).

8

Turn cylinder head and pull out valve (9)

 Mark valves relative to the installation location when removing a number of valves (9).

 Installation: Lubricate valve stem (9) lightly with engine oil, push in valve (9) and lay spacer (11) (height about 5.3 mm) under valve disk.

Pay attention to marking.

9

Install in the reverse order