Compression System; Poor Idle Speed Performance; Poor Medium And High Speed Performance - Yamaha TDM850 1996 Service Manual

STARTING FAILURE/HARD STARTING/POOR IDLE SPEED
PERFORMANCE/POOR MEDIUM AND HIGH SPEED PERFORMANCE

COMPRESSION SYSTEM

Cylinder and cylinder head
S Loose spark plug
S Loose cylinder head or cylinder
S Broken cylinder head gasket
S Worn, damaged or seized cylinder
S Improperly sealed valve
S Improperly contacted valve and valve seat
S Improper valve timing
S Broken valve spring

POOR IDLE SPEED PERFORMANCE

POOR IDLE SPEED PERFORMANCE
Carburetor
S Improperly returned starter plunger
S Loose pilot jet
S Clogged pilot air jet
S Improperly synchronized carburetors
S Improperly adjusted idle speed (throttle stop
screw)
S Improper throttle cable free play
S Flooded carburetor

POOR MEDIUM AND HIGH SPEED PERFORMANCE

POOR MEDIUM AND HIGH SPEED PERFORMANCE
Refer to "Starting failure/Hard starting". (Fuel system, electrical system, compression system and valve
train.)
Carburetor
S Diaphragm malfunction
S Improperly adjusted fuel level
S Clogged or loose main jet
Piston and piston rings
S Improperly installed piston ring
S Worn, fatigued or broken piston ring
S Seized piston ring
S Seized or damaged piston
Crankcase and crankshaft
S Improperly seated crankcase
S Seized crankshaft
Electrical system
S Faulty battery
S Faulty spark plug
S Faulty ignitor unit
S Faulty pickup coil
S Faulty ignition coil
Valve train
S Improperly adjsted valve clearance
Air Cleaner
S Clogged air filter
Air cleaner
S Clogged air filter element
Fuel pump
S Faulty fuel pump
9-2
TRBL
SHTG