I have a 87 Formula 242 ss with a 454 magnum and an alpha drive. I bought the boat a few month ago and have had a problem since i bought it. It will shift fine when not in water and when the boat isnt started but as soon as i have it in the water and i put it into reverse to get off trailer i go to shift back inti nuetral and it comes off the controlls. The bracket inside the controls bends. Does anyone know what would cause this to happen? Any suggestions will be helpful. Thanks

that could be a binding lower shift cable. try shifting with the drive in different positions.

oh, nice boat by the way. that is exactly what I have but mine is in pieces getting the transom replaced.
So dont feel bad, at least yours is wet

On the shift bracket is a switch, #14 in the illustration. While at idle, press in on that switch and it should stall the engine. If it does not you have to find out why. It is designed so that as you shift it momentarily presses that switch and stutters the engine, this unloads the shift dogs and allows the drive to come out of gear.

^^^I agree....i have the exact same boat in an LS. Your momentary interrupt is the problem. Check to see if the switch kills the motor. if it does not then you have a bad connection or a bad switch. that switch should kill power to the coil for a split second so the dog clutches will release in the drive. the drive will shift out of the water b/c there is no load/pressure on the prop, so there is no pressure on the dog clutches and they release without killing the engine. once in the water there is too much load on the prop and there is no way to get it to release besides that cutout switch. you can also (in the water - just to test) pull the boat into gear, then shut the key off, pull it out of gear, and start it back up to see if its actually out of gear (or in another gear).

What they said - see:

http://go-fast.com/mercruiser_alpha_shift_problems.htm

thank you for the help. I will be sure to check that switch tomorrow.

454 mag with alpha,,,,,YU BETTER BE VERRRRY carefull.....that drive isnt gonna last long with the hp outta that motor,start saving for a bravo conversion!!

That's exactly right, that's why the switch. All Bravos cannot be shifted under load. You will streach the cable,

Setting your idle low is also helpful 500rpm if you can get there...you can then throttle to a good idle speed after shifting. As important as the switch setting in my humble opinion (esp when the switch doesn't work) .
Setting them up is a challenge as you may have already discovered- the manual doesn't seem to be of much help...