Yamaha F30B 2018 Service Manual page 318

Item
Shift link/shift cable
Spark plug
Spark plug caps/
spark plug wires
Throttle link/throttle
cable
Timing belt
Thermostat
Cowling lock lever
Valve clearance
Water pump
Wire harness
Lead
(Yamaha)
Meter/gauge
Fuel tank (Yamaha
portable tank)
Check the shift cable when the remote control lever or gear shift
lever is moved to the N position.
Not at the proper position  Adjust the shift cable joints or check
the related parts.
Clean the electrodes using a spark plug cleaner.
Check the spark plug.
Electrodes are damaged/worn or insulator is abnormal color 
Replace.
Check the spark plug gap.
Out of specification  Replace.
Measure the spark plug cap resistance.
Out of specification  Replace.
Check the throttle cable when the remote control lever is moved to
the N position (remote control model).
Check the throttle cable when the throttle grip is turned to the fully
closed position (tiller handle model).
Not at the proper position  Adjust the throttle cable joint or check
the related parts.
Check the timing belt.
Cracked/damage/worn  Replace.
Measure the thermostat valve opening.
Out of specification  Replace.
Check the fitting by pushing the top cowling.
Looseness/rattling  Adjust or replace the top cowling stopper.
Check the valve clearance.
Out of specification  Adjust.
Check the water pump housing.
Deformed  Replace.
Check the impeller, insert cartridge, and outer plate cartridge.
Cracked/worn  Replace.
Check the impeller key and keyway in the drive shaft.
Deformed/worn  Replace.
Check the wire harness coupler and lead coupler connections.
Check the meter/gauge display.
Check the fuel tank
Cracked/damage  Replace.
Leaking  Check the related parts.
Dirt/residue  Clean.
Procedures
10-13
General periodic maintenance
See
3-6
—
7-40
5-29
5-30
3-6
7-15
7-46
10-21
7-2
8-4
—
—
—