bucking problem in a mustang

Question
Ihave recently acquired a 9-year-old mustang gelding who apparently was broke by placing a saddle on him and riding the "buck" out of him.. now he is a routine bucker and we never know what is going to set him off.. he seems to enjoy people sometimes and other times he walks around with his ears laid back constantly.  He was captured at the age of 7.. I do not know much about his history but do know that his last owner could not handle him and was riding him with a combination bit.. the few times tht he did ride him over the 1 1/2 year period of time that he owned him.   I put him back in the round pen and have been riding him in there.. He does fairly well and has only bucked once while in there.. in a larger paddock, he will buck at the drop of a hat.. let me describe what I am classifying as a buck.. he drops his head and all 4s come off of the ground!!! any advice on getting this touch lil guy back on the right track would be wonderful. As of now, I have started him back on square one.  Using the round pen to lunge, drive etc. Have also been using items to desensitize him and have him in a corral right next to my house wherehe is exposed to all sorts of typical house stimuli...kids, dogs.. vehicles.. lawnmowers etc..


Thanks in advance for your time and expertise.

Kay

Answer
Kay, You're doing what has to be done, starting all over again.  Problem is, you are having to re-write nearly 2 yrs. of mis-handling.  It's going to take time and patience.  How long?  I can't tell you. Only he can.  Maybe months, maybe years.  His basic personality comes into play here. That will have a lot to do with the length of time needed to change his attitude.  Is he with other horses?  If not he may be unhappy because he's not used to being alone.

Please be especially careful with the tack you use as far as fit.  If it's uncomfortable then he's got a legitimate reason for bucking/poor attitude.  I would personally put some effort in trying to figure out what is behind his attitude.  That can be a myriad number of things either physical or mental.  But that's me.  I get inside the heads of problem horses that get sent to me.  

At this point all I can offer is encouragement and caution patience.  You have a nice horse there, once you "fix" him.  I have to assume he's had all the correct routine care including dental work each year?  If he's not had his teeth floated and his mouth checked by an equine dentist that might be part of the problem.  There are so many things that can go into making a horse moody and irritable.  For mares that's a given but geldings can become depressed, irritable etc. when things aren't right with them.  

Hang in there, they all come around in the end.  I know this is a lot to do.  I've done it more times than I would like to have done it.  Fixing a "broken" horse takes a lot of love and patience.