APRILIA RSV mille 956X Service And Repair Manual page 159

ENGINE
ASSEMBLING THE VALVES IN THE HEAD
NOTE
Have the appropriate special tools
– (3) cod. 0277210 (valve guide assembly pad):
– (8) cod. 0276479 (valve spring compression tool);
– (9) cod. 8140179 (valve disassembly and reassembly
bow).
a
CAUTION
During assembly, make sure the valves and valve lift-
er buckets are refitted where they belong inside the
head.
Insert the valve spring housing cap (1) through the
valve guide.
Fit a new valve stem oil seal (2) with the assembly pad
(3).
Oil the valve stem and carefully insert the valve (4) in-
side the valve guide.
NOTE
Take care not to damage the valve stem oil seal
(2).
Check head pressure loss on a plate (Bosch or Sun-
tester).
NOTE
If the pressure loss is less than 7%, this means
valve tightness is correct.
Fit the valve springs (5-6) and valve spring caps (7).
NOTE
The intake and exhaust valve springs are identi-
cal, but must always be fitted so that the coloured mark-
ing is at the top since the winding of the springs is pro-
gressive.
Preload the valve springs with the spring compressor
(8) and special clamping device (9) and insert them in
the valve cotters (10).
NOTE
Apply grease on the valve cotters (10) to make
assembly easier.
When releasing the clamping device (9), make sure the
valve cotters (10) are inserted perfectly in the valve
grooves.
Where necessary, use a plastic hammer to tap them in
gently.
a
CAUTION
Make sure the valve springs are inserted properly. If
the valves are fitted obliquely, they will inevitably
cause the valve stems to break.
O = Motor oil.
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to hand:
RSV mille