Preheat the barbecue for medium heat and place a large sheet of foil onto the grate.
Melt the margarine and honey together in a small saucepan over medium heat. Reduce heat to low and cook gently, stirring occasionally until slightly thickened, about 5 minutes. Do not let the sauce boil.
Thread a peach quarter, a plum quarter, a banana piece and a strawberry onto each skewer. Place the skewers onto the foil on the preheated grill; spoon margarine-honey mixture over each skewer.
Barbecue until the fruit is softened and the sauce has thickened and cooked onto the fruit, about 5 minutes. Flip the skewers, spoon more margarine-honey sauce over each and barbecue for about 5 more minutes on the other side.