how long do I cook a 4 lb beef roast on a rotisserie
1 Insert meat thermometer into center of beef roast. 2  Cook on rotisserie over drip pan in closed grill over INDIRECT HEAT for about 1 1/2 hours (rare = internal temperature of 140ÂºF or medium = internal temperature of 160ÂºF).3  Baste beef roast with the reserved marinade while barbecuing. Discard used marinade. 2  Preheat grill to medium heat. 3  Insert meat thermometer into center of beef roast. 4  Cook on rotisserie over drip pan in closed grill over INDIRECT HEAT for about 1 1/2 hours (rare = internal temperature of 140ÂºF or medium = internal temperature of 160ÂºF).