Tuning; Carburetor Tuning - Yamaha VK540EF Service Manual

CARBURETOR TUNING

ESS00083

TUNING

ESS00084
CARBURETOR TUNING
The carburetors are set at the factory to run at
temperatures of 0_C X –20_C (32_F X –4_F)
at sea level. If the machine is to be operated un-
der conditions other than those specified
above, the carburetors must be properly ad-
justed. Special care should be taken in carbure-
tor setting so that the pistons will not be dam-
aged or will not seize.
CAUTION:
Engine oil is mixed with fuel just before the
fuel enters the carburetors. During initial
fuel flow to the carburetors, it is not always
possible to supply the optimum fuel/oil mix-
ture depending on the throttle opening.
Therefore, after the carburetors have been
tuned or maintained, or after the float cham-
bers are removed for cleaning or jet replace-
ment, be sure to idle the engine for about
three minutes in order to avoid engine
trouble.
CAUTION:
Before performing the carburetor tuning,
make sure that the following items are set to
specification.
S Engine idle speed
S Throttle cable freeplay
S Carburetor synchronization
S Starter cable freeplay
S Oil pump cable freeplay
ESS00085
Carburetor tuning data
1. Standard specifications
Type
A
Manufacturer
B
Main jet (M.J.)
C
Pilot jet (P.J.)
D
Pilot screw (P.S.)
E
Float height
F
Idle speed
G
2-31
INSP
ADJ
B38-34/1
MIKUNI
#141.3
#90
1-1/4 turn out
12 X 16 mm
(0.47 X 0.63 in)
1,200 100 r/min