The "Periodic Maintenance / Lubrication Intervals" schedule is taken directly from a 2001 edition Yamaha YW50AP factory service manual. Before starting any work, always consult the manual for your scooter's model & year and be sure you know what you're doing.

YW50 Periodic Maintenance / Lubrication Intervals

Item	Remarks	Type	Break-in 300 mi (500 km)	Thereafter every 2,000 mi (3,000 km) or 6 months	Thereafter every 4,000 mi (6,000 km) or 12 months
Fuel line*	Check fuel hose for cracks or damage. Replace if necessary	-	-	X	X
Spark plug	Inspect/Clean or replace as required	NGK BPR7HS .02-.03" (0.6 - 0.7mm) gap	X	X	X
Air filter	Wash & damp with oil	-	-	X	X
Front brake*	Check fluid level and look for leaks. Replace pads if needed	DOT 3 or DOT 4 brake fluid	X	X	X
Rear brake*	Adjust free play. Replace shoes if needed	-	X	X	X
Wheels*	Check balance, runout, and look for damage	-	-	X	X
Tires*	Check tread depth and look for damage. Front 29 psi, Rear 29 psi	-	X	X	X
Wheel bearings*	Check bearings for looseness or damage	Medium weight wheel bearing grease	-	X	X
Steering bearings*	Check bearing play and steering for roughness	Medium weight wheel bearing grease	X	X	X
Chassis Fasteners*	Make sure all nuts, bolts, and screws are properly tightened	-	X	X	X
Centerstand	Check operation and repair if necessary	-	X	X	X
Front fork*	Check operation and look for oil leakage	-	-	X	X
Rear shock assembly*	Check operation and repair as required	-	X	X	X
Carburetor*	Check engine idling speed. Adjust if necessary	-	-	X	X
Autolube pump*	Check. Adjust and bleed air as needed.	-	X	-	X
Final transmission oil*	Replace (warm engine before draining)	0.11 liter SAE 10W30 type SE motor oil or GL gear oil	Replace every 8000 miles (12,000 km) or 24 months	X	X
V-Belt*	Check for cracks and wear. Replace every 6000 miles (9000 km).	-			X

*These items require special skills, tools, or information. It is recommended that they be serviced by a Yamaha dealer.