Before you buy it, check to see what the total travel up and down is. You want to be able to get it down far enough, but not too far into the water. Based on your serial number, download the owner's manual for your engine.
http://marine.honda.com/support/manuals/models/BF
Look for the pages that address how far in the water that the motor should be.
If you are getting a mount made by garlick, their website shows the amount of travel and I seem to remember even drawings.
When you go to mount it, follow the instructions carefully. Since the motor is light, you should fasten it to the mounting and hold the whole thing in place against your transom. Once you determine that it will go into the water to the point that you want it, mark the transom with some tape. Then reset the mount to full up and see if the motor will come out of the water all the way.
At that point, then tilt the motor up (if you are going to tilt it up) and make sure that the hood does not hit boat and that the front of the motor clears the mounting.
Check it a couple of times. Measure a bunch of times, different ways (if you can)....to be sure that you get the same placement.
I should have said this first, but check on the other side of the transom that there is access that you can through bolt the mount. If it does not come with the mount, you may also want to make a backing plate to put on the inside to help spread the load.
Measure....check......measure......check.......measure......check
Put masking tape on the fiberglass so that when you mark it and mess up, you will not mark your boat. The masking tape will also help to minimize any cracking of the fiberglass when you drill. This will sound crazy...but.....when you drill you holes.....start drilling the holes with the drill going in reverse until you get through the layer of gelcoat. Then you can drill normally. I do this to keep the drill from grabbing the gelcoat layer and cutting into it too quickly, causing cracks and chips.
Of course, when you do the final mounting be sure to use a good marine caulk to seal around the bolts.
Good luck.
Mike