Poor Medium-And-High-Speed Performance/Faulty Clutch; Poor Medium-And-High-Speed Performance; Engine; Fuel System - Yamaha YJ125S Service Manual

POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE/

EAS00849
POOR MEDIUM-AND-HIGH-SPEED
PERFORMANCE
Refer to "STARTING FAILURES".

ENGINE

Air filter
8Clogged air filter element
Air intake system
8Bent, clogged or disconnected carbure-
tor air vent hose
8Clogged or leaking air duct

FUEL SYSTEM

Carburetor
8Faulty diaphragm
8Incorrect fuel level
8Loose or clogged main jet
8Faulty accelerating pump
Fuel cock
8Faulty fuel cock

FAULTY CLUTCH

EAS00853
FAULTY CLUTCH
ENGINE OPERATES BUT SCOOTER WILL
NOT MOVE
V-belt
8Bent, damaged or worn V-belt
8Slipping V-belt
Primary pulley cam and primary pulley slider
8Damaged or worn primary pulley cam
8Damaged or worn primary pulley slider
Clutch spring(s)
8Damaged clutch spring
Transmission gears
8Damaged transmission gear

CLUTCH SLIPS

Clutch shoe springs
8Damaged, loose or worn clutch shoe
spring
Clutch shoes
8Damaged or worn clutch shoe
Primary sliding sheave
8Seized primary sliding sheave

POOR STARTING PERFORMANCE

V-belt
8V-belt slips
8Oil or grease on the V-belt
Primary sliding sheave
8Faulty operation
8Worn pin groove
8Worn pin
Clutch shoes
8Bent, damaged or worn clutch shoe
8-3
TRBL
SHTG