I have an older '83 Johnson 9.9 electric start/tiller mounted to a SS swing down/up bracket. So far no troubles with a padlock (frozen now due to salt) on the handles, but they can unbolt the plastic board and away they go.

Kicker motor over the handle lock, a "cryptonite" cable lock, my own non-lethal booby trap AND a dog (been wanting one of those anyway) are in order. If they get through all that, they're nuts, I'm away, the neighbors aren't home and the motor will be torn up so bad it won't be worth anything.

Good luck to y'all!!

Matt