This is my favorite recipe for barbecued chicken thighs.
From Companies Coming "Year-Round Grilling" cookbook
Around 12 boneless, skinless chicken thighs (about 1 1/2 pounds)
1/4 cup ketchup
1/4 cup white vinegar
2 Tbsp soy sauce
1 Tbsp worcestershire sauce
1 tsp dried crushed chilies
1 Tbsp sugar
Pound chicken flat to even thickness.
Combine remaining 6 ingredients in a medium bowl or resealable freezer bag. Add chicken. Stir to coat. Cover or seal. Marinate in refrigerator for at least 2 hours or overnight. Drain and discard marinade. Preheat barbecue. Cook chicken on grill till done.. About 20-25 minutes.. Thighs don't take very long to cook so watch them!