Valves - APRILIA RSV mille 956X Service And Repair Manual

ENGINE

3.6.29 VALVES

Carefully read 0.2.1 (PRECAUTIONS AND GENERAL
INFORMATIONS).
a
CAUTION
The seat (1) on the head of the valve is reinforced by
means of inductive hardening.
For this reason, the seat cannot be reground and, in-
stead, the valve must be replaced.
Grinding with abrasive paste is nonetheless permit-
ted, whilst it is prohibited to regrind a valve at the end
on the valve stem.
Clean the valves of all residual combustion products.
Check the seat (1) on the valve head with a line.
The surface of the seat must not be concave; where
necessary, replace it.
Check the diameter of the stem with a micrometer:
– intake valve:
wear limit (2) min. Ø 5.950 mm;
– exhaust valve:
wear limit (2) min. Ø 5.935 mm.
Check the eccentricity of the valve:
– valve stem:
permissible eccentricity (3) max. 0.05 mm;
– valve head:
permissible eccentricity (4) max. 0.05 mm.
Check whether the fastening grooves (5) of the valve
cotters are in a perfect state of repair.
VALVE SPRINGS
Measure and visually inspect the valve springs to check
for breakage, distortion or loss of tension; measure the
length of the springs in the release position.
– Valve springs:
wear limit (6) min. 43.4 mm;
– Valve springs:
wear limit (7) min. 40.9 mm.
NOTE
Worn spring valves may result in a reduction in
engine power and increased noise from the valve assem-
bly.
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RSV mille