How to re-install lower unit 1972 80 hp mercury

[jake66]

when re-installing the lower unit how do I reset the linkage. When I put the footing back on it won't shift, it shifted before I replaced the water pump. Also where can I find a key switch for this boat
thanks for any help.

 

[Chris1956]

Re: How to re-install lower unit 1972 80 hp mercury

You just need the ign key, or the switch? Ign keys are avail at any dealer. There are only about 10 different ones.

To install gearcase. Set control to neutral. What gear are you in? Forward I will bet. Turn shift shaft CCW until it clicks and staus in neutral. You will need to use a cresent wrench and light pressure to get it to shift. Now grease both splines and shove driveshaft up into midsection (motor tilted up). Turn flywheel until crankshaft and driveshaft splines mate. Now wiggle gearcase into position using fingers to tighten nuts. You may need to rock throttle handle a bit to mate shift shaft splines.

 

[jake66]

Re: How to re-install lower unit 1972 80 hp mercury

I need a new ignition switch for it and mine is the one with the black remote control with blue stripe. Mine is a 5 wire switch all I can find is a six wire switch. Also do you know if there is a thermostat in in this motor.

I have tried that, but when I put the lower unit in neutral and the shifter in neutral, when I install it, the footing shifts into gear. How can I keep it from doing that.

thanks for writing me and helping with the info.

 

[Chris1956]

Re: How to re-install lower unit 1972 80 hp mercury

There is no thermostat on that motor. Six wire ign switch is likely push to choke type. You can leave the grey wire off of the ign switch and continue to use choke button.

Gearcase should stay in neutral, when installing. Not sure what your issue is.

 

[jake66]

Re: How to re-install lower unit 1972 80 hp mercury

thanks for your help, I will try it again to see what happens I may have another question later. Hopefully I can get it to work.
thanks

 

[schematic]

Re: How to re-install lower unit 1972 80 hp mercury

Don't rotate prop shaft when determining neutral on the gearcase. Use the driveshaft instead. Rotating propshaft has a tendency to loosen the detent's grab on the shift cam and will allow gearcase to easily jump out of neutral with any touch of the shift shaft.
Use only the driveshaft in clockwise rotation to find neutral

 

[jagans]

Re: How to re-install lower unit 1972 80 hp mercury

Slather Nickel Anti-Seize compound on that Spline before you mate them, and make sure your water pump vanes are in the speed cup in the right direction. Rolling left when looking from the top.

 

[Chris1956]

Re: How to re-install lower unit 1972 80 hp mercury

Actually, use marine grease on the splines. Turn the driveshaft CW when installing the impeller. The vanes will find their own curve.