I was helping a buddy take a kicker bracket off a boat he just bought ( the knuckle head wants a swim step instead) and we were going through the instructions that came with the thing when I read that you should not trailer your boat with the motor mounted on the bracket. I have always trailered my boats with the kicker on the bracket. I figured that if it would hold the thing in the water and was not over the weight limit it would be ok to trailer with the motor attached. Am I an accident looking for a place to happen? What is your experience? Ever been driving down the road and look out the mirror to see your prized four stroke kicker hanging to the transom by a piece of rope or cable?
By the way if you want to buy a great looking used kicker bracket check the classifieds section of this site.

I always keep mine on, but it mounts directly to the transom. My buddy has his motor on a bracket, but leaves his connected, also.

I don't think there's a problem with it unless you started driving over a lot of really rough, bumpy roads. That might cause some added stress to the transom, especially on a glass boat.

However, if it's mounted correctly with the proper backing I don't see where it would hurt to trailer it all together. As added precaution, I guess you could tie it up securely to avoid any extra movement and take some stress off the bracket and transom.

When I purchased my Hewescraft Searunner a couple of years ago, I had them put an 8 hp on with a bracket. Within a month, the bracket had put a 2 inch crack in my transom! The problem was they used the cheaper bracket, that was rated within 5 pounds on my kicker. It also bounced like crazy. several times people stopped me on the way to Neah Bay to tell me that the motor was going to come off! I took it back to the dealer and they welded an aluminum plate behind the transom, and upgraded to the bigger bracket. (no charge!!) I have'nt had a problem since! Some of those kickers are just too heavy to take on and off. I told them that was unreasonable and they needed to make it so I could drive with it on all the time. They did.

I have a Yamaha 9.9 which is heavy mounted on my transom. Been there for 10 years. When it was mounted I had a piece of 1/4" thick aluminum mounted inside the boat. The boat is a SeaSport which has a transom that is about 1 and 1/1" thick or more. The bracket was then bolted through the transom and the aluminum plate. Have never had a problem. I would caution you to use a rope or bungie to lash the motor to something on your transom though, otherwise the steering arm will swing it back and forth all the time.