I have an '86 Johnson 15hp outboard that is still running nicely. The only problem is that it does not have a mechanism which would allow me to "lock" it in a centered position (where it cannot turn to either side). I have it mounted on the back of my 28' sailboat, and being able to lock it in place would be nice. Did these engines not have this type of lock? (sorry if there is an actual name for this type of doohickey) Is there an add-on bracket of some sort, or do I need to fabricate one? Thanks in advance for any advice.