1977 OMC 120, lost drive and reverse

[DuckPlucker]

Hi, I have a 1977 OMC 120, last time on the water I was coming in ro the dock and when i put it in reverse, it just reved up, didnt go into gear.

Fast forward a few weeks and im out again, this time im at the dock and it wont go into any gears. Just revs real high regardless if its in drive or reverse.

I have it out of the water, key tyrned to ON position and the shift lever in drive. I can hand turn the prop either direction, it literally spinns freely.

This is my first boat, but I am pretty mechanically inclined. Any thoughts on what I should do.

Sorry for the long read, and thanks in advance for any answers.

 

[racerone]

Sounds like the splines on the water pump shaft are rusted out ( stripped ) fairly common event..-----Or you have lost power to the shift switch.----Find the wires that go down into the lower unit and see if you have 12 volts on green with control in forward ( key turned on )----12 volts on blue for reverse.

 

[Scott Danforth]

First, welcome aboard

Scond, your druve will need to come apart and you will need to inspect the vertical driveshaft splines

Third, i flaged the post to be moved to the OMC forum

 

[DuckPlucker]

Sounds like the splines on the water pump shaft are rusted out ( stripped ) fairly common event..-----Or you have lost power to the shift switch.----Find the wires that go down into the lower unit and see if you have 12 volts on green with control in forward ( key turned on )----12 volts on blue for reverse.

Ok looks like i have no power to shift switch.
Where is said shift switch? Do I need to replace it or follow wire's to see where I am loosing power.

 

[racerone]

If it is the standard control box from factory the switch is in the control box.----They are proud of those switches.----Check all the wiring.----May also be a loose wire on ignition switch.