Boat doesn't move in Drive

[pontiacwarrior]

Hello this is my first post here,Today I put my 77 four winns boat in the water to see if it floats and runs good I bought it as a basket case,It has a 1972 mercury 80 hp motor ,will it runs good and has reverse but no drive ,it will move the boat in reverse but when it is put in drive the boat justs sits there. The prop spins and the motor revs up but nothing ... The way it revved up I should have been up on land but the boat just stayed in the sameplace.....could any one help me on this the prop is a 13 1/2 X 19 pitch
Thanks Robert

 

[diaric]

Re: Boat doesn't move in Drive

if the prop is spinning, then driveshaft should be turning ok. mark the hub of the prop across. run again and check if line the same. your checking to see if rubber hub is shot. can be repaired at a prop shop if it is

 

[pontiacwarrior]

Re: Boat doesn't move in Drive

It has a rebuilt prop from Michigan prop

 

[diaric]

Re: Boat doesn't move in Drive

should still check it. wrong prop rotation? make sure thrust washer there and prop nut tisht.

 

[Sig_Mech]

Re: Boat doesn't move in Drive

Pontiac, are you sure you had the shift shaft and linkage lined up correctly when you installed the LU? You say that you have reverse and it moves the boat but are you sure it's being fully engaged in forward? You say that the prop spins when in forward gear but does look like the prop is turning at the same rpm as the motor? The prop could be spinning from nothing more than friction from the circulation of lube in the LU. Make sure that the forward gears are fully engaging. You may need to drop the LU and realign the shift shaft then reinstall it.