[ERA Chas]

O,
If you have some experience: remove the sight plugs from the fuel bowls, (engine cold and off) letting fuel drain out. Dry off everything, start engine. Loosen lock nut on needle valve (the large slotted screw head on top of each bowl) and slowly turn counter clockwise so fuel just stops seeping out of the sight plugs. Lock the nut on that setting and go on to the other needle.
Go for a ride and adjust the float levels until you have smooth operation.
Good luck.