Assembly Of Cylinder Head; Overrunningclutch 1N - Rotax 912-UL Repair Manual

6.6.7) Rockerarm
Check rocker arm shaft and rocker arm bearing surface for wear. Inspect valve stem
contact area and ball cup of rocker arm. Signs of wear indicate lack of oil. Slight
rework of contact area on rocker arm is allowed. Check oil bore for free passage.
Dimension of
rocker arm bore
rocker arm shaft
rocker arm radial clearance
wcar at valve stem contact
6.7) Re-assembly of cylinder head
new mm
(in)
12,060+ 12,080 (0,475 + 0A76)
12,A3+ 12,0Y (
0A73)
0,A26+ 0,057 (0,001+ 0,002)
0,000
wear limit mm (in.)
12,20 (0,490)
1t,98 (0,472)
0,12 (0,12)
0,25 (0,010)
If renewing the rocker arm shaft, press it into position with ends symmetrically projecting. At
renewal of coolant bend, mark existing position first, to ensure corect positioning of the new
one. Apply OMNIFIT 230 M to thread of bend, fit it, and allow c. 10 min. for curing at 80o C
(176" F).
Place valve spring support in position and fit new valve stem seal (on inlet side only). Insert
pre-oiled valves, place inner and outer valve spring and spring retainer in position, compress
valve springs by utilizing fitting jig and clamp (see chapter 6.6.2).Insert valve cotters and
release springs. Apply MOLYKOTE G-N to both ends of rocker arm shaft, fit left and right
rocker arm and secure with circlip lZxl.
I NOTE: Sharp edge of circlips to point outwards.
The cylinder head temperature is observed by a pick-up fitted in a tapped hole M I 0 on cylinder
head 2 or 3.
Additional temperature readings of the coolant are not required.
6.8) Overrunning clutch
Visual check for accumulation of oil
sludge in ovemrnning clutch housing O.
For cleaning, remove retaining ring O,
compress circlip on overrunning clutch
0 and twist out sprag unit and clean
components. Measure clutch housing
and ovemrnning gear for wear. The cir-
cumferential helical spring @ must not
be loose or winding. Sprags O must be
freely moving and the surface free of
damage. Checkengagementface inhous-
ing. At detectable wear of gripping faces
housing.
exchange corresponding parts. Inspect taper bore in
'Rm:r,912-UL