Yamaha VK540EK Owner's Manual page 49

Main jet replacement
Replace the main jet according to the setting chart which
is available at a Yamaha dealer.
WARNING
@
G Never remove the drain plug or the float chamber
while the engine is hot.
Fuel will flow out from the float chamber which
could ignite and cause injury.
G Place a rag under the carburetor before removing
the drain plug or float chamber to catch any
spilled fuel.
G Handle fuel with care: it is HIGHLY FLAMMABLE.
@
Standard main jet:
#141.3
CD-04E
Main jet
Small No.
Large No.
1. Loosen the carburetor clamps and turn over the car-
buretor.
2. Pinch the fuel hose to prevent fuel flowing.
3. Remove the drain plug and install the proper main jet.
4. Assemble by reversing the removal steps.
WARNING
@
Make sure that the throttle outer cable is firmly
seated in the holder and throttle operates smoothly
after assembling the carburetor.
@
8-8
Mixture
Lean
Rich
Condition
Warm weather
High altitude
Cold weather
Low altitude