Yamaha YZ125(R)/LC, Owner'S Service Manual

Page: 518 / 568

7-7
TUN
SETTING
EC719071
Jet needle adjustment
(For EUROPE)
On the carburetors used in the YZ125, the main
nozzle is a non disassembly type, so it can not
be replaced. Therefore, carburetor setting
requires the change of the jet needle.
1. The jet needle setting parts, having the same
taper angle, are available in different straight
portion diameters and in different taper start-
ing positions.
<Example>
6CHY6-82
Diameter of straight portion
Clip position
Taper angle
Changing from 6CHY6-82 to 6CHY5-82 has
the same effect as a lowering of 0.5 clip
position.
A
Difference in straight portion dia.
B
Difference in clip position
a
Reference needle
b
0.5 leaner
6CHY6-81
6CHY6-82
6CHY6-83
6CHY5-82
6CHY6-82
Standard jet needle 6CHY6-82
Diameter of straight
Rich Lean
Clip position
portion
ø2.810 mm (0.1106 in) ø2.820 mm (0.1110 in) ø2.830 mm (0.1114 in)
Rich 1 richer 6CHY6-81-5th groove 6CHY6-82-5th groove 6CHY6-83-5th groove
0.5 richer 6CHY5-81-5th groove 6CHY5-82-5th groove 6CHY5-83-5th groove
STD 6CHY6-81-4th groove 6CHY6-82-4th groove 6CHY6-83-4th groove
0.5 leaner 6CHY5-81-4th groove 6CHY5-82-4th groove 6CHY5-83-4th groove
Lean 1 leaner 6CHY6-81-3rd groove 6CHY6-82-3rd groove 6CHY6-83-3rd groove