carb adjustment for yamaha r5

[Still biking]

I have a 72 yamaha R5 that when I adjust carbs its best running point is only about 3/4 turn out on air screws.  book says it should be 1 and 3/4  what could be wrong?

[m in sc]

have you verified the pilot jet size is correct? if its too small it would need an adjustment like that

[quocle603]

Confirm everything is good to go: Engine warmed up, time properly, no possible airleak, carbs cleaned and synced. Start at 1.5 turns out from flush and work your way in/out to see max rpm?