1) Cylinder Head - Disassembly - Rotax 914 F Maintenance Manual

14.5.1) Cylinder head - disassembly

See Pic. 245.
If the cylinder head is not removed but the rocker arms should be dismantled,
turn crankshaft to set the piston of the respective cylinder to ignition T.D.C.
and thus only little pressure remains on the rocker arm. Depress rocker arm
with test lever 877 690 towards hydraulic valve tappet. Now the rocker arm
is completely released and the rocker arm shaft can be removed.
N NOTE:
1
3
cylinder head to approx. 180° C (360° F). Extract tubes and remove any glue
00280
residues from bore. Apply LOCTITE 648 on oil tubes in the area of the two
grooves and twist and push tube into position in the preheated cylinder head.
N NOTE:
Pic. 245
At renewal of bent socket for coolant, mark its position, heat cylinder head to
approx. 80° C (176 °F) and turn out socket. Remove residues of securing
agent and check threads. Apply LOCTITE 648 on cylinder head and on bent
socket and turn socket into the cold cylinder head. Let cylinder cure for
approx. 10 minutes at 80° C (176° F).
If there are oil carbon residues on the sealing face with cylinder, remove them
carefully. Check sealing face for planeness.
At slight wear, valve and valve seat may be seal-lapped, using emery paste.
Clean cylinder head and single components in gasoline or kerosine. Check
sealing face of cylinder head, and if need be, true up along with cylinder, but
only slight rework (max. 0,1 mm / 0.004 in. per side) is allowed.
Renew valve stem seals. If the engine has been "run hot", check in any case
hardness of cylinder head and cylinder material, see Chapter 12.4.7).
Date
Page
2003 03 01
248
The hexagon of the cap nut may be in an unfavourable
position as to prevent removal of the rocker arm shaft. In this
case loosen the nut.
2
Withdraw rocker arm shaft and remove both rocker arms.
Compress valve springs utilizing valve spring mounting device Q,
part no. 877 380 and clamp W or similar tool and lift out valve cotters.
Release valve spring. Remove valve spring retainer and both springs,
and withdraw valve.
N NOTE:
Prior to removal of valves, clear burrs which may be
present on valve stems to prevent damage to valve stem
seal and valve guide. Mark valves coordinately.
Repeat procedure for the second valve. Clean cylinder head.
Check oil return tubes for leaks (visual check). If leaking in the area
E the respective tubes must be renewed. For this procedure heat the
Apply LOCTITE only on the cold part!
Main
914 F
Reference
Modification no.
- 5 -