technical data YAMAHA YFZ50 2021 Owners Manual
Page 80 of 126
9-3
9
EBU36872Periodic maintenance chart: Emission control systemTIPFor ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals in-
stead.
 For odometer or hour meter-equipped vehicles, follow the month maintenance interval if the ATV isn’t
ridden for the stated distance or engine operating hours.
 Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills. NO. ITEM CHECK OR MAINTENANCE 
JOB INITIAL
EVERY
Whichev-
er comes  first month136612
km (mi) 240 
(150) 1300 
(800) 2500 
(1600) 2500 
(1600) 5000 
(3200)
hours 20 80 160 160 320
1 *Fuel line • Check fuel hoses for cracks or other damage, and 
replace if necessary. √√√
2 Spark plug • Check condition and clean, regap, or replace if 
necessary. √√√√√
3 *Va l ve s • Check valve clearance and adjust if necessary. √ √√√
4 *Carburetor • Check starter (choke) operation and correct if 
necessary.
• Check engine idling speed and adjust if neces- sary. √ √√√
5 *Crankcase breath-
er system • Check breather hose for cracks or other damage, 
and replace if necessary. √√√
UBW464E0.book  Page 3  Thursday, January 23, 2020  2:42 PM 
Page 82 of 126
9-5
9
EBU36892Periodic maintenance chart: General maintenance and lubricationTIPFor ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals in-
stead.
 For odometer or hour meter-equipped vehicles, follow the month maintenance interval if the ATV isn’t
ridden for the stated distance or engine operating hours.
 Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills. NO. ITEM CHECK OR MAINTENANCE 
JOB INITIAL
EVERY
Whichev-
er comes  first month136612
km (mi) 240 
(150) 1300 
(800) 2500 
(1600) 2500 
(1600) 5000 
(3200)
hours 20 80 160 160 320
1 Air filter element • Clean and replace if necessary. Every 20–40 hours (more often in wet or 
dusty areas)
2 Air filter check hose • Clean. √√√√√
3 *Front brake • Check operation and correct if necessary.
• Check brake lever free play and adjust if neces-
sary. √√√√√
• Replace brake shoes. Whenever worn to the limit
4 *Rear brake • Check operation and correct if necessary.
• Check brake lever free play and adjust if neces-
sary. √√√√√
• Replace brake shoes. Whenever worn to the limit
UBW464E0.book  Page 5  Thursday, January 23, 2020  2:42 PM