Mercury 305 CID, Service Manual, Page: 111 / 967

ALPHA DRIVES - WITH DRIVE SHAFT EXTENSIONS - 2B-7 90-823225--1 1096
! CAUTION
Engine MUST BE aligned correctly to achieve
proper engine operation and to prevent damage
to drive shaft. If drive shaft is run at an incorrect
angle, damage to universal joint bearings may re-
sult.
6. Position base of protractor on drive shaft, then
raise or lower engine (as boat construction per-
mits) until indicator needle is 1 degree to 3 de-
grees on either side of reading taken in Step 1.
Record this reading in the following chart for later
use.
70238
a - Drive Shaft
b - Protractor
c - Output Shaft Flange
b
c
a
Reading from Step 6. __________ degrees to the
_________ side of reference mark.
7. Adjust stringer height so that the stringers just
contact the engine mount bases.
! CAUTION
Failure to properly position output shaft flange
(as described following) may result in bearing
damage.
8. Relieve hoist tension from engine, then slide en-
gine fore or aft as needed to obtain 1/4 in. (6 mm)
between flange shoulder and extension shaft
housing bearing, as shown.
72591
a - Flange Shoulder
b - Bearing
c - 1/4 In. (6 mm)
b
c
a
9. Position engine for correct engine and drive shaft
lateral alignment as follows:
a. Measure the length of (a) and (b) to the cen-
ters of bolt holes. They MUST BE EQUAL. If
they are not equal, slide the aft and forward
ends of the engine equal amounts in opposite
directions to obtain equal lengths for (a) and
(b).
70246
These Dimensions Must Be Equal
b
a
b. Recheck Step 8. If Step 8 is not as specified,
adjust and recheck Step 9a. Continue this
process until both Steps 8 and 9a are as spe-
cified.