My gelding has inconsistant gaits. I have been trying to get him to get him to stick with one kind of trot-- but he will start with a jog so I ask him to speed up, then it is fine for one round around the arena... but then he quickens to something like trotting race horse. Also, at the canter he will have a beautiful medium collected canter and then the next time around the ring I can't get him to stop acting like a race horse! He just gets so out of control for apparently no reason other than being excited.
He has a pretty soft mouth so I try not to use anything other than light contact and soft leg. He is currently being ridden in a eggbutt snaffle. Should I try a slightly more severe bit? When he gets going a little too fast I use half halts (reign and seat) but they really don't seem to work like they should.When he does have a good pace I reward him and talk to him and then let him walk, but his canter usually starts off like that but ends all strung out because I can't get him to stop! I feel like I should try another bit that will give me more control when he gets like this so I don't have to be so rough on his mouth when he starts flying around the ring.
If so, any suggestions on the type of bit or any other thing I can use?