In medium bowl, combine all marinade ingredients; mix well. Add beef cubes; stir to coat. Refrigerate 15 minutes to marinate.
Heat grill. Remove beef cubes from marinade; reserve marinade. On each of eight 7-inch or four 14-inch metal skewers, alternately thread beef cubes, onion pieces, bell pepper pieces, and potato wedges.
When ready to grill, place kabobs on gas grill over medium-high heat or on charcoal grill 4 to 6 inches from medium-high coals. Cook 12 to 16 minutes or until beef is of desired doneness, turning to brown all sides of beef cubes and brushing frequently with reserved marinade. Do not add any marinade during last 4 minutes of grilling. Discard any remaining marinade.