APRILIA 8140172, Service And Repair Manual

Page: 156 / 279

ENGINE
RSV mille
3 - 73
a
CAUTION
La testata o il guidavalvola si danneggia se non si
usa il MOLYKOTE
®
G-N.
◆ Apply a coat of MOLYKOTE
®
G-N on the head hole
and on the valve guide assembly edge.
NOTE
Have the appropriate special tool
&
(8) to hand
(cod. 0277695 valve guide oil seal assembly pad).
◆ Using the assembly pad (8), insert the new valve guide
in the head, working from the oil chamber towards the
combustion chamber until the assembly punch reaches
a level position.
NOTE
The exhaust valve and intake valve guides are
different.
The difference consists in the fact that the intake valve
guide has a longer smoothed surface (9).
◆ Check how much the head (10) of the valve guide pro-
trudes on the camshaft side.
(10) Protrusion = 13.3 ± 0.2 mm.
◆ Bore the valve guide with a
∅
6 F7 reamer.
Hole of the valve guide Ø 6.006 – 6.018 mm.
NOTE
Use cutting fluid only to lubricate the reamer.
The reamer should only be turned in the cutting direction,
never in the opposite direction, and cleaned of tailings at
frequent intervals, again always removing it in the direc-
tion of the cut.
◆ Having bored the valve guide, clean the head thorough-
ly and grind the valve seat (11), smoothing the valve
seat with a valve seat reconditioning device, and grind
the valve, see 3.6.29 (VALVES - VALVE SEATS).
◆ Check the contact mark using the relevant marking
paste (Prussian blue).