Yamaha YZF-R1 2020 Service Manual page 421

EAS31666
CHECKING THE PRIMARY INJECTORS
(BEFORE REMOVING)
1. Check:
• Injectors
Use the diagnostic code numbers "36"–"39".
Refer to "SELF-DIAGNOSTIC FUNCTION
AND DIAGNOSTIC CODE TABLE" on page
9-40.
EAS31667
REMOVING THE PRIMARY INJECTORS
EWA17330
WARNING
• Check the injectors in a well-ventilated area
free of combustible materials. Make sure
that there is no smoking or use of electric
tools in the vicinity of the injectors.
• Be careful when disconnecting the fuel
hose. Any remaining pressure in the fuel
hose may cause the fuel to spray out. Place
a container or rag under the hose to catch
any fuel that spills. Always clean up any
spilt fuel immediately.
• Turn the main switch to "OFF" and discon-
nect the negative battery lead from the bat-
tery terminal before removing the injectors.
1. Remove:
• Fuel rail
a. Remove the fuel rail screws.
EAS31668
CHECKING THE PRIMARY INJECTORS
1. Check:
• Injectors
Obstruction → Replace and check the fuel
pump/fuel supply system.
Deposit → Replace.
Damage → Replace.
2. Check:
• Injector resistance
Refer to "CHECKING THE FUEL INJEC-
TORS" on page 8-51.
EAS30769
CHECKING AND CLEANING THE THROTTLE
BODIES
TIP
Clean the throttle bodies only if they cannot be
synchronized using the bypass air screws. Be-
fore cleaning the throttle bodies, check the fol-
lowing items:
• Valve clearance
• Spark plugs
• Air filter element
• Throttle body joints
• Fuel hoses
• Air induction system
• Exhaust system
• Crankcase breather hose
• Vacuum hose
EWA17340
WARNING
If the throttle bodies are subjected to strong
shocks or dropped during cleaning, replace
them as a set.
1. Check:
• Throttle bodies
Cracks/damage → Replace the throttle bod-
ies as a set.
2. Clean:
• Throttle bodies
ECA21540
NOTICE
• Observe the following precautions; other-
wise, the throttle bodies may not operate
properly.
• Do not subject the throttle bodies to exces-
sive force.
• Clean the throttle bodies in the recom-
mended cleaning solvent.
• Do not use any caustic carburetor cleaning
solution.
• Do not apply cleaning solvent directly to
any plastic parts, sensors, or seals.
• Be careful not to remove the white paint
mark that identifies the standard throttle
body.
• Do not turn the bypass air screws "a"; oth-
erwise, the throttle body synchronization
will be affected.
Recommended cleaning solvent
Yamaha Oil & Brake Cleaner
a
a. Place the throttle bodies on a flat surface
with the air filter case side facing up.
7-14
THROTTLE BODIES
a