Mercury MERCRUISER, Service Manual, Page: 135 / 566

IMPORTANT: The engine bed must position the engine so that a minimum of 6 mm (1/4 in.) up and down adjustment still
exists on all four mounts after performing initial alignment. This is necessary to allow for the final engine alignment.
ZF Marine 63IV
a - Propeller shaft
b - Propeller shaft flange
c - Transmission output flange
d - No visible gap allowed
6. Ensure that all four mounts are still positioned properly. Fasten the mounts to the engine bed with 10 mm (3/8 in.) diameter
lag bolts of sufficient length and flat washers. Tighten lag bolts securely.
7. Ensure that the quick drain oil fitting is more than 13 mm (1/2 in.) above the boat bottom.
8. Disconnect the overhead hoist and remove the sling.
Final Engine Alignment—TowSport, Inboard
IMPORTANT: Engine alignment must be checked with the boat in the water, fuel tanks filled, and with a normal load onboard.
1. Check the mating faces on the transmission output flange and propeller shaft flange to ensure that they are clean and flat.
2. Center the propeller shaft in the shaft log as follows:
a. Push down and then lift the shaft as far as it will move. Then place the shaft in the middle of the movement.
b. Move the shaft to port and then to starboard as far as the shaft will move. Then place the shaft in the middle of the
movement.
c. With the shaft in the center of the shaft log as determined by the above procedures, align the engine with the shaft.
Typical down angle (V-drive similar)
a - Up
b - Port
c - Down
d - Starboard
a
b
c
d
7616
a
d
b
c
7619
Installation
90-8M0099748 eng DECEMBER 2015 © 2016 Mercury Marine Page 2B-31