Poor Medium And High Speed Performance; Poor Speed Performance - Yamaha YP250 Service Manual

POOR MEDIUM AND HIGH SPEED PERFORMANCE

EB902000
POOR MEDIUM AND HIGH SPEED PERFORMANCE
POOR MEDIUM AND HIGH SPEED PERFORMANCE
Refer to "STARTING FAILURE/HARD STARTING" section. (Fuel system, electrical system, compres-
sion system and valve train)
Carburetor
D Improperly adjusted fuel level
D Clogged main nozzle
D Clogged or loose pilot jet
YP******

POOR SPEED PERFORMANCE

POOR SPEED PERFORMANCE
Ignition system
D Dirty spark plug
D Improper heat range
D Faulty ignitor unit
D Faulty pick up coil
Fuel system
D Clogged fuel tank cap breather hole
D Clogged air cleaner element
D Clooged jet
D Improperly adjusted fuel level
D Improper carburetor air vent hose setting
Air cleaner
D Clogged air cleaner element
Compression system
D Worn cylinder
D Worn or seized piston ring
D Cylinder head gasket broken
D Cylinder gasket broken
D Carbon deposit build-up
D Improperly adjusted valve clearance
D Improperly contacted valve and valve seat
D Faulty valve timing
Clutch
D Refer to "CLUTCH SLIPPING/DRAGGING"
section
Engine oil
D Improper oil level (low or over oil level)
D Improper quality (Low oil viscosity)
D Deterioration
D Clogged oil passage
Brakes
D Dragging brake
9-3
TRBL
SHTG