Step 1

In a medium bowl, mix soy sauce, light brown sugar, distilled white vinegar, garlic powder, seasoned salt, garlic pepper seasoning, and lemon-lime flavored carbonated beverage. Reserve about 1/2 cup of this marinade for basting. Place steak in a large resealable plastic bag. Cover with the remaining marinade, and seal. Refrigerate for 8 hours, or overnight.

Step 2

Bring a saucepan of water to a boil. Add green peppers, and cook for 1 minute, just to blanch. Drain, and set aside.

Step 3

Preheat grill for high heat. Thread steak, green peppers, mushrooms, tomatoes, and pineapple onto skewers in an alternating fashion. Discard marinade and the bag.

Step 4

Lightly oil the grill grate. Cook kabobs on the prepared grill for 10 minutes, or to desired doneness. Baste frequently with reserved marinade during the last 5 minutes of cooking.