If using bamboo skewers, soak them in water for at least 30 minutes before grilling.
Cut the chicken, pineapple, red bell peppers, and onion into even 1 1/2-inch pieces.
Thread the chicken, pineapple, bell pepper, and onion onto the skewers.
Wrap or weave the bacon around the chicken, pineapple, bell pepper, and onion pieces as the skewers are assembled.
Use approximately 2 strips of bacon per skewer, depending on the size of the ingredients.
Brush each prepared kebab lightly and evenly with vegetable oil or olive oil.
Preheat the grill to medium-high heat.
Place the kebabs on the preheated grill.
Grill for 10 to 15 minutes, turning occasionally, until the chicken is fully cooked, the bacon is browned, and the pineapple and vegetables are lightly charred.
Ensure the chicken reaches an internal temperature of 165°F.
Brush the kebabs generously with the prepared Hawaiian sauce during the final minutes of grilling or immediately after removing them from the grill.
Serve warm with additional sauce, if desired.