Technical data

C
ylinder Head, Timing Gear
Detach Decompression lever handle, clamping sleeve on handle, spring shaft,
Remove valve poppets, spring plate with valve spring, cone halves, valve guides
Rework
5
- Remove decompression lever from the
underside of the cylinder head (10)
- Unscrew the M10 nut and unscrew stud bolt.
- Remove the spring
- Remove retaining pin with pointed pliers
- Unscrew inner clamping sleeve on gear
segment and remove shaft and gear segment.
- Remove valves & valve springs (11)
- Press down the spring retainers
WARNING
Danger of injury due to spring retainers and
valve keys popping out.
- Loosen both key halves while applying pressure
from below and remove with pointed pliers.
- Remove cap and washer from under the valve
spring
- Remove valve
- Press out the valve guides from below
NOTE
When pressing in the new valve guides,
when parts are cold note minimum force
of 1000 N (approx 100 kp)
- Ream the valve guides
- Rework leaky valve seats with a 45
o
valve seat
cutter. Mill only enough to remove spots from
valve seats.
- Reseat valves using auxiliary tool
- No 74 64 1 333 539