Mercruiser 120 Shift Interrupter Switch

[Mercruiser 120]

I have a 1981 boat that had a seized 2.5L and I put a 1970 Mercruiser 120 in it 2.5.
Boat runs great. There is just a little problem when I bring it into neutral it is a bit harder than normal, it stays in forward for a second but my gearshift is in neutral and then just goes into neutral.
I have to test my shift interrupter but does anyone have a wiring diagram maybe for a 1981 120 4cyl and then a 1970 diagram. Everything that shifts the boat and the drive are all 1981.
Thank you for any help. Someone gave me the diagrams for both months ago so I could match up the colours and get everything working.

 

[Maclin]

This can be an adjustment is needed on the lower shift cable, or that the cable is worn beyond tolerances for adjusting. If it comes out of gear finally without turning the engine off then the switch is probably ok, just not getting the nudge it needs at the right time to be in synch with the shifter.

Mods--probably need to move this to the Mercruiser setion...