Yamaha SXV70SJ Supplementary Service Manual page 176

CARBURETOR TUNING
A
Standard main jet
B
Main jet whose diameter is 10% smaller than
standard
C
Main jet whose diameter is 10% larger than
standard
SCH2820
A
2
No.
B
1
No.
C
3
No.
SCH2825
CAUTION:
If the air silencer box is removed from the carbu-
retors, the change in pressure in the intake will
create a lean mixture that may cause severe
engine damage. The air silencer box has no effect
on performance characteristics and must be se-
cured to the carburetors during carburetor tuning
and adjustment. Also, it must always be in place
when the engine is operated. Regularly clean the
silencer and keep it free from obstructions.
SCH2830
2-43
INSP
ADJ
position
position
position