Follow the linkage from your hydro pedal to the control arm about midway between the front and rear tires on the right-hand side. In the center of the control arm where it pivots is a 12mm bolt head and a slot cut in the shaft that faces out from the frame. Loosen the bolt and using a screwdriver in the slot you can turn the eccentric to adjust neutral.
To adjust, jack right front tire off the ground, make sure the rear axle is disengaged and start the engine. Have a helper set in the seat and release the brake off. You can watch the tire and adjust to neutral. Retighten the 12mm bolt to lock eccentric.