Service manual

EC719072
Jet needle adjustment
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>
6CHY5-80
Diameter of straight portion
Clip position
Taper angle
In the case of the same number of clip posi-
tion, changing from 6CHY5-80 to 6CHY6-80
has the same effect as a rising of 0.5-clip
position. And in the case of the same num-
ber of clip position, changing from 6CHY5-80
to 6CHY18-80 has the same effect as a ris-
ing of 2-clip position.
A Difference in straight portion dia.
B Difference in clip position
a Reference needle
b 0.5 richer
c 2 richer
7-6
TUN
SETTING
6CHY5-79
6CHY5-80
6CHY5-81
6CHY5-80
6CHY6-80
b
a
B
A
c
6CHY18-80
Standard jet needle 6CHY5-80
Diameter of straight
Rich Lean
Clip position
portion
ø2.78 mm (0.1094 in) ø2.79 mm (0.1098 in) ø2.80 mm (0.1102 in) ø2.81 mm (0.1106 in) ø2.82 mm (0.1110 in)
Rich 1.5 richer 6CHY6-78-5 6CHY6-79-5 6CHY6-80-5 6CHY6-81-5 6CHY6-82-5
1 richer
6CHY18-78-3 6CHY18-79-3 6CHY18-80-3 6CHY18-81-3 6CHY18-82-3
6CHY5-78-5 6CHY5-79-5 6CHY5-80-5 6CHY5-81-5 6CHY5-82-5
0.5 richer 6CHY6-78-4 6CHY6-79-4 6CHY6-80-4 6CHY6-81-4 6CHY6-82-4
STD 6CHY5-78-4 6CHY5-79-4 6CHY5-80-4 6CHY5-81-4 6CHY5-82-4
0.5 leaner 6CHY6-78-3 6CHY6-79-3 6CHY6-80-3 6CHY6-81-3 6CHY6-82-3
1 leaner
6CHY18-78-1 6CHY18-79-1 6CHY18-80-1 6CHY18-81-1 6CHY18-82-1
Lean 6CHY5-78-3 6CHY5-79-3 6CHY5-80-3 6CHY5-81-3 6CHY5-82-3
1C3-28199-10 241 04.5.17, 9:30:45 PM