Yamaha EF2400iS Service Manual page 97

ENGINE SPEED DOES NOT INCREASE
Check if the electric equipment consumes too much
wattage for this generator.
GOOD
Check air filter element for dirt.
GOOD
Check spark plug for dirt and check spark plug gap.
GOOD
Check valve clearance.
GOOD
Check if main passages such as, the main jet, in the
carburetor are clogged.
GOOD
Check for air suction due to a damaged throttle shaft
seal, carburetor joint, or gasket.
GOOD
Check compression using compression gauge.
GOOD
Check valve face and valve seat for wear.
GOOD
Check if the marks on the crankshaft and camshaft
are aligned.
GOOD
Check if there is seizure or wear on piston, piston ring,
or cylinder.
GOOD
Check the condition of the throttle control system.
Refer to "THROTTLE CONTROL SYSTEM".
TOO MUCH
NO GOOD
NO GOOD
NO GOOD
NO GOOD
NO GOOD
TOO HIGH
TOO LOW
NO GOOD
NO GOOD
SEIZURE OR
WEAR
6-4
TRBL
ENGINE
Use a generator with a larger capacity.
Clean.
Clean or adjust.
Adjust.
Disassemble or clean.
Disassemble or replace.
Decarbonize combustion chamber if
there are carbon deposits.
Resurface or replace.
Correct.
Rebore or replace.