Trouble with turning?

Question
Hi there, I'm currently putting some miles on a 5 year old QH so that he can be used as a trail horse but it seems that no matter what type of bit or saddle or bridle I use he won't turn right. If I am leading him, he turns fine but the minute I get on his back he refusing the turn and even tried throwing me over a fence to refuse the turn. I'm not sure what to do as I have checked his teeth and they seem fine.
Can you please help me?

Answer
Hello there!
My sister just had a baby so I apoligize for the delay. In this situation it sounds like your horse is asking you to slow down, he does not understand how to respond to you so he is reacting. If he is better on the ground lets start there. Stand next to him where the saddle is and slowly slide your hand down the rein (halter or bridle is fine), now we would love it if he kept his feet still so lets go very slowly. Start slowly and with rhythm "knocking" on the rein, it will feel like you are milking the rein like you would milk a cow-bump-bump-bump etc. You are asking him to come on over with his head! Every time he starts to bring his head over at all, and it may start with him just looking at you, stop for a bit. Then start again asking for more bend in his neck until he is bent to you like he is looking for a hug- then drop the rein completely. When this gets really good on each side you can get on and try the same thing. If he moves, no problem, just wait until he holds still (it might take a minute) to release the rein. The release says "Right answer!"  When you start riding if he starts to feel heavy to turn go back to this exercise and get him soft and listening again then go back and try just turning again. You are letting him know in no way is he in trouble but life is alot easier if he listens to your subtle cues. If you find you are still getting into trouble let me know, I have several recipes to soften up a tight horse.
Best Wishes