Halve the leeks lengthwise, then rinse well and pat dry. In a small bowl, whisk the honey and lemon juice; season with salt and pepper. Brush the cut sides of the leeks with the honey mixture. Wrap each leek half with 1 bacon slice.
If using a charcoal grill, heat to medium- high, then push the coals to one side. If using a gas grill, light one side to medium- high. Place the leeks on the cool side of the grill. Cook, turning once, until the bacon is cooked through and the leeks are tender, about 15 minutes. Move the leeks to the hot side of the grill. Cook, turning once, until the bacon is crispy and the leeks begin to char, 2 to 3 minutes longer.