driving levers adjustment

[Glyn Robinson]

when both levers are push all the way forward, it always drifts to the left. how do i correct this?

 

[gainestruk]

On my Husqvarna there is a tracking knob on the left lever right at base of lever you just turn right or left to set left control lever to match right side, mine was a little faster on left so driving at full speed I turned knob to right until it matched the right control.