Locating Center Line Of The Outboard; Drilling Outboard Mounting Holes - Mercury Two-stroke series Installation Manual

Locating Center Line Of The
Outboard
Locate (and mark with pencil) the vertical centerline
(a) of boat transom.
A
C
a - Centerline of Transom
NOTE: Dimensions "A" & "B" and "C" & "D" are equal
length.
During installation of dual outboards,
IMPORTANT:
the following is recommended. A minimum of 221/2
inches (570mm) centerline to centerline width is rec-
ommended. This is required to alleviate cowling in-
terference during lock to lock turns if one outboard
would be in the full tilt position, while the other out-
board(s) are in the vertical running position.

Drilling Outboard Mounting Holes

IMPORTANT: Before drilling any mounting holes,
carefully read "Determining Recommended Out-
board Mounting Height," preceding. There is a
3/4 inch (19mm) difference between outboard
mounting holes in transom brackets.
WARNING
DO NOT, under any circumstances, allow upper
outboard mounting bolts to be closer than 1 inch
(25.4mm) from top of boat transom. Upper
mounting bolts must never be installed thru
shims.
90-830234R3 DECEMBER 1997
B
a
D
NOTE: When drilling into a fiberglass boat, place
masking tape directly onto boat where mounting
holes will be drilled to help prevent fiberglass from
chipping.
Use a 17/32 inch (13.5mm) diameter drill bit and drill
4 mounting holes perpendicular to and thru transom.
IMPORTANT: If using "Transom Drilling Fixture"
(part number 91–98234A2), use drill guide holes
marked "A" when drilling outboard mounting
holes.
b
a
a – Centerline of Transom
b – Transom Drilling Fixture (91–98234A2)
IMPORTANT INFORMATION - 1D-3