Poor Medium-And-High-Speed Performance; Engine; Fuel System; Faulty Clutch - Yamaha CS50 Service Manual

POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE/

EAS00848
POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE
Refer to "STARTING FAILURES".

ENGINE

Air filter
• Clogged air filter element

FUEL SYSTEM

Carburetor(s)
• Faulty diaphragm
• Incorrect fuel level
• Loose or clogged main jet
Fuel pump
• Faulty fuel pump
EAS00853

FAULTY CLUTCH

ENGINE OPERATES BUT
SCOOTER WILL NOT MOVE
V-belt
• Bent, damaged or worn V-belt
• Slipping V-belt
Primary pulley cam and primary pulley slider
• Damaged or worn primary pulley cam
• Damaged or worn primary pulley slider
Clutch spring(s)
• Damaged clutch spring
Transmission gear(s)
• Damaged transmission gear

CLUTCH SLIPS

Clutch shoe spring(s)
• Damaged, loose or worn clutch shoe spring
Clutch shoe(s)
• Damaged or worn clutch shoe
Primary sliding sheave
• Seized primary sliding sheave
FAULTY CLUTCH

POOR STARTING PERFORMANCE

V-belt
• V-belt slips
• Oil or grease on the V-belt
Primary sliding sheave
• Faulty operation
• Worn pin groove
• Worn pin
Clutch shoe(s)
• Bent, damaged or worn clutch shoe

POOR SPEED PERFORMANCE

V-belt
• Oil or grease on the V-belt
Primary pulley weight(s)
• Faulty operation
• Worn primary pulley weight
Primary fixed sheave
• Worn primary fixed sheave
Primary sliding sheave
• Worn primary sliding sheave
Secondary fixed sheave
• Worn secondary fixed sheave
Secondary sliding sheave
• Worn secondary sliding sheave
9-3
TRBL
SHTG