Yamaha YZ450F(S) Owner's Service Manual page 602

c
b
d
Diameter of straight portion
Clip position
Rich 1 richer
0.5 richer
STD
0.5 leaner
1 leaner
Lean
NCYQ-4
NCVQ-4
NDJQ-4
Rich
M N
NCVM-5 NCVN-5
– – NCYN-4
NCVM-4 NCVN-4
– – NDJN-4
NCVM-3 NCVN-3
SETTING
Jet needle adjustment
(For USA)
The jet needle is adjusted by changing it.
Standard jet needle
The jet needle setting parts, having the same
taper angle, are available in different straight
portion diameters and in different taper starting
positions.
<Example>
NCVQ - 4
b
Reference needle
c
0.5 richer
d
0.5 leaner
Changing from NCVQ-4 to NDJQ-4 has the
same effect as a lowering of 0.5 clip position.
P Q
NCVP-5 NCVQ-5
NCYP-4 NCYQ-4
NCVP-4 NCVQ-4
NDJP-4 NDJQ-4
NCVP-3 NCVQ-3
7 - 7
T U N
NCVQ
Clip position
Diameter a of straight portion
R S
NCVR-5 NCVS-5
NCYR-4 NCYS-4
NCVR-4 NCVS-4
NDJR-4 NDJS-4
NCVR-3 NCVS-3
Lean
T
NCVT-5
– –
NCVT-4
– –
NCVT-3