Yamaha U-MAX G27A Owner's/Operator's Manual page 84

Engine oil:
Type
Recommended engine oil classification
Quantity:
Oil change
Transmission:
Type
V-belt width and outer line length
V-belt wear limit
Transmission oil:
Type
Quantity
Steering system:
Type
Model
YAMALUBE 4 (10W30) or SAE 10W30
API Service SE type or higher
0.9 L (0.79 Imp qt, 0.95 US qt)
V-belt automatic centrifugal
31 x 1010 mm (1.22 x 39.76 in)
27.9 mm (1.10 in)
SAE 90 gear oil
0.42 L (0.37 Imp qt, 0.44 US qt)
Rack and pinion (G27A)
Worm and pin (G28A)
10-3
G27A/G28A