slimjim - Don't mean to offend you in any way but when did parenting become an option? When your wife had her son, there was no clause that said ...."and you can choose whether to continue parenting, if your particular child causes you too much trouble, you can always send him away..."
If he were 18 - I'd say yes but he's 14 for God's sake!
You and the boy in question need to go away together for a weekend, in a tent, with no distractions around you. All you will have to do is exist together, not talk, talk about superficial stuff and then talk about important things. Neither of you will be able to 'leave the room' or escape. I guarantee barriers will be brought down and the unsaid things in your step son's mind will slowly come out in words, thoughts and feelings.