In bowl combine honey, vinegar, curry powder and tarragon. Remove grids from barbecue. Place one or two shallow drip pans filled with water or stock (you can also add a splash of white on the lava rocks.)
Preheat barbecue to high setting. Arrange chickens on spit, making sure they are evenly balanced. Brush with honey basting sauce and install rotisserie on barbecue with drip pans directly underneath. Barbecue at high setting for 10 minutes.
Reduce heat to medium and roast chickens, with lid down for about 1 ½ to 2 hours, basting every 30 minutes with sauce until thermometer inserted in thickest part of thigh registers 185F.
Remove from barbecue, season with salt and pepper and tent with foil. Let stand 10 minutes before carving.
Indirect cooking method for gas barbecues with two burners: Place a shallow metal or foil pan (not necessary to add water) under one side of grill to catch drippings.
Preheat both sides of barbecue on high setting. Tie wings and legs of chicken with string; brush lightly with oil. Place chicken breast-side down on hot grill and cook for 2 minutes.
Turn chicken on its side and grill for two minutes; continue to grill chicken on other side for two minutes until browned all over. Place chicken breast-side up n the side of barbecue with sauce and roast chicken with lid down for about 90 minutes brushing occasionally with sauce, until chicken is done.
If you have charcoal barbecue with a lid: Move the hot coals to the sides of barbecue and place a drip pan in center. Place chicken or roast on grill with drip pan directly underneath. Cook with lid down and use a meat thermometer to gauge when foods are cooked.
