Re: How do I start my mariner without controlls?
Probably has a starter solenoid (probably top front) with four wires hooked to its posts, two large and two small. One of the big wires is the big red positive wire from the battery, across from that is the other big post, that one goes to the starter (probably big yellow wire). Hold a big screwdriver across these two posts and you'll activate the starter (assuming the battery is good and hooked up properly, including grounded to block). Hold it good and tight and pull it away firmly after it starts (or after no more than two or three seconds, or if you see a lot of sparks), or you'll weld the screwdriver to the posts.
Safer alternative (aside from controls and ignition switch) would be to get a momentary push switch in a hand-held device with some big wires and alligator clips made for this purpose, I think it's called a "remote start switch" or somesuch.