First of all thank you for any help, its greatly appreciated!!! 
I have bought the manual for this year, but is my boat a Alpha, Alpha1???? The serial # is 3645613 Mercury Marine 120 h.p. someone told me its a GM 153 inline 4. My problem is it will not shift out of reverse!!! We took it out fishing and we backed up away from some tree stumps and its been stuck ever since! We had to cruise across the lake in reverse! (how embarrassing) We had to be towed to dock!! I've read a lot of posts on here about shifting issues my head is spinning!!!! Would greatly appreciate some help!!! going out on my boat and fishing is my ME time and I have a grandson I'd love to take out and teach to fish!!Thanks again!!!
I have bought the manual for this year, but is my boat a Alpha, Alpha1???? The serial # is 3645613 Mercury Marine 120 h.p. someone told me its a GM 153 inline 4. My problem is it will not shift out of reverse!!! We took it out fishing and we backed up away from some tree stumps and its been stuck ever since! We had to cruise across the lake in reverse! (how embarrassing) We had to be towed to dock!! I've read a lot of posts on here about shifting issues my head is spinning!!!! Would greatly appreciate some help!!! going out on my boat and fishing is my ME time and I have a grandson I'd love to take out and teach to fish!!Thanks again!!!