Lower unit trouble!!

[auntiekim]

I have a 1979 140 hp mercury outboard. We replaced the water pump and are having major trouble getting the lower unit timed correctly (so far only has forward gear worked fine before taking it apart) also having trouble getting it to bolt back to engine.

 

[GA_Boater]

Welcome aboard. I re-titled your topic so no one is confused.

Drop the lower unit and use a pair of pliers to gently rotate the shift shaft into neutral. In neutral the prop spins easily in both directions. Put the remote control in neutral and remove the spark plugs. Then make sure the water pipe is fully seated in the bottom of the motor.

Offer up the lower unit and rotate the flywheel counterclockwise until the drive shaft splines engage and get a couple of bolts started to hold it in place. At this point there is still a gap between the lower unit and midsection. Look through the gap to make sure the water pipe is lined up with the water pump outlet and start to snug up the rest of the bolts and nuts. Make sure the prop still spins in both directions. Tighten all the bolts and nuts, then shift to forward with the remote and the prop is locked in one direction and clicks in the other. Shift to reverse and the prop is locked in both directions. Back to neutral for one last free spinning prop check, re-check all the bolts and nuts and go boating.

Good luck, Auntiekim.

 

[auntiekim]

How do I know when it's in neutral? I read that it was suppose to click

 

[GA_Boater]

Turn the prop. If only turn in one direction and clicks, it's in forward. Not turning, it's in reverse. And easily turns in both directions with no clicking, it's in neutral.

 

[Chris1956]

Turn the shift shaft CCW when she is in forward gear to find neutral. It will click in and stay in neutral. Make sure the plastic shift rod guide is in the midsection, and not the gearcase. That will help the upper shift rod align with the lower shift rod.

 

[auntiekim]

The only way I know to explain this is for someone to call my boyfriend and talk to him about it

 

[merc850]

This is how I do it in about 60 sec.: Turn the LU shift shaft by hand counter-clockwise until it
stops, then with Vise Grips tight on the bottom of the shaft turn it a
few more degrees CCW until it clicks into a stop, this
should be neutral - check by turning propshaft --
prop should spin freely.
Put control in N and go ahead and attach LU to driveshaft housing some turning of the flywheel will help the DS splines align.
Do not shift into reverse unless you turn the prop at the same time.