Yamaha YZ250 Owner's Service Manual page 164

PILOT AIR SCREW ADJUSTMENT
3-14
4. Remove:
9 Oil drain bolt 1
9 Oil filler cap 2
Drain the transmission oil.
5. Install:
9 Aluminum washer
9 Oil drain bolt 1
6. Fill:
9 Transmission oil
Recommended oil:
Yamalube 4 (10W-30) or SAE
10W-30 type SE motor oil
Oil capacity
(periodic oil change):
0.75 L (0.66 Imp qt, 0.79 US qt)
7. Check:
9 Oil leakage
8. Check:
9 Transmission oil level
9. Install:
9 Oil filler cap 2
EC35L021
PILOT AIR SCREW ADJUSTMENT
1. Adjust:
9 Pilot air screw 1
Adjusting steps:
9 Turn in the pilot air screw until it is lightly
seated.
9 Turn out the pilot air screw by the factory-set
number of turns.
NOTE:
To optimize the fuel flow at a smaller throttle
opening, each machine's pilot air screw has
been individually set at the factory. Before
adjusting the pilot air screw, turn it in fully and
count the number of turns. Record this num-
ber as the factory-set number of turns out.
Pilot air screw:
1 turn out
*7/8 turns out
(for reference only)
*For EUROPE
INSP
ADJ
20 Nm (2.0 m•kg, 14 ft•lb)