76-80 mercury compatibility questions

[glennwingman]

Im replacing a 76 merc 650 65 hp triple with a 1979/80 merc. 90 hp. Few questions:
Will the power trim/tilt from my 65 fit my 90? its got two rams, two hoses each, that seem to replace the "assist shocks" I really hope so....

Second, My "control box," the nuetral throttle/gearshift, will that work on my 90 hp motor? the steering attachment on the two motors looks the same.

And finally the wiring...what am I looking at as far as having to wire this motor? I have my complete harness in the boat, as well as a supposed complete harness for my newer motor.

If this seems like a bit much to answer, I'll simplify: What is compatible between the two motors, and what isnt?

Thanks very much, I've been "trolling" on this site for a while, it seems like a great resource full of good people. I hope I can help someone on here someday as I hope you'll help me with this! Thanks in advance, Patrick.

 

[Faztbullet]

Re: 76-80 mercury compatibility questions

Yes your 65 trim will work and the control will to if its a 79 model as it has ADI ignition. I would not use the old controls(65) as the motor ends are different an some splicing would be needed to make work.

 

[glennwingman]

Re: 76-80 mercury compatibility questions

Yes your 65 trim will work and the control will to if its a 79 model as it has ADI ignition. I would not use the old controls(65) as the motor ends are different an some splicing would be needed to make work.

Ok, so trim will work. Great. The rest of your post confuses me a bit though...
Adi ignition? What's that exactly? I guess I was thinking aside from positive and negative battery power, electric choke, ignition, the motor wiring should be pretty simple, right?

While building a motor stand for my new motor I put a #2 bit driver through my thumbnail and decidedto be done for the day, so I didn't have a chance to look over all that it came with.

 

[glennwingman]

Re: 76-80 mercury compatibility questions

ok...so its an 80-81 motor. With that being said, will my same ignition/throttle control work, or will I need to use the one that came with the motor? Im really hoping to keep as much of my current controls as possible. Also, the steering system seems to go through the "pivot point" then attach to one of these

http://www.iboats.com/T-R-Steering-...47775485--**********.506730669--view_id.40158 which attaches to my steering linkage on the front of the motor. Im hoping this will all swap over?

 

[Faztbullet]

Re: 76-80 mercury compatibility questions

If your old engine has no distributer cap and 3 coils it is a ADI ignition, if it has a distributer cap and 1 coil its a CD ignition. If its the CD ignition you box will not work at all due to wiring and keyswitch difference. If it a ADI it will work but the end that plugs into harness is may be different, if they are the round barrel plug it will swap with no problem and your steering arm will work.

 

[glennwingman]

Re: 76-80 mercury compatibility questions

Awesome, thanks so much for all of your help guys, I feel better about attempting this swap now, seems like the worst trouble I'll have (aside from lifting the engine) will be splicing 6 wires...and that I can do!