Mariner 100, Service Manual, Page: 366 / 391

7A-25 ENGINE ATTACHMENTS 90-13645--2 495
Installing Outboard Motor on
Transom
Determining Recommended Outboard
Mounting Height
a
b
c
d
e
e
Boat Speed (MPH) – Maximum Speed Anticipated
IMPORTANT: Add 5 in. (12.7cm) to Mounting
Height for “XL” Models.
a - This solid line is recommended to determine the outboard
mounting height dimension. Use transom mounting bolt
holes that will position outboard nearest to the
recommended height. After engine break-in (if necessary),
raise or lower outboard one position at a time to attain best
performance. See “Important” immediately following.
IMPORTANT: Increasing the height of outboard generally
will provide the following: 1) Less steering torque, 2) more
top speed, 3) greater boat stability, but, 4) will cause more
prop “break loose” which may be particularly noticeable
when planing off or with load.
b - These broken lines represent the extremes of known
successful outboard mounting height dimensions.
c - This line may be preferred to determine outboard mounting
height dimension, if maximum speed is the only objective.
d - This line may be preferred to determine outboard mounting
height dimension for dual outboard installation.
e - Outboard mounting height (height of outboard transom
bracket from bottom of boat transom). For heights over 22 in.
(560mm), a propeller, that is specifically designed for
surfacing operation, such as the “Chopper” series, usually is
preferred.
Locate Centerline of Boat Transom
Locate (and mark with pencil) vertical centerline (a) of
boat transom, as shown.
a
b c
d e
NOTE: Dimensions “b” and “c” and “d” and “e” are
equal length.