Determining Recommended Outboard Mounting Height - Mercury 225 OPTIMAX DTS Installation Manual

Determining Recommended Outboard Mounting Height

e
1.
2.
3.
Increasing the mounting height will usually:
• Less steering torque.
• Increase top speed.
• Increase boat stability.
• Cause propeller to break loose during planning.
90-10234050
63.5 cm
(25 in.)
60.9 cm
(24 in.)
e
58.4 cm
(23 in.)
56.0 cm
(22 in.)
53.3 cm
(21 in.)
50.8 cm
(20 in.)
48.2 cm
(19 in.)
a - The solid line is recommended to determine the outboard mouting height.
b - The broken lines represent the extremes of known successful outboard
mounting height dimensions.
c - The line may be prefered to determine outboard mounting height dimesion,
if maximum speed is the only objective.
d - The line may be prefered to determine outboard mounting height dimesion
for dual outboard installation.
e - Outboard mounting height (height of outboard mounting brackets from
bottom of boat transom). For heights over 56.0 cm (22 in.) a propeller, that
is designed for surfacing operation is usually prefered.
f - Maximum boat speed (mph) anticipated.
The outboard should be mounted high enough on the transom so that exhaust relief hole will stay at
least 25.4 mm (1 in.) above the water line when the engine is running at idle speed. Having the exhaust
relief hole above the water line will prevent exhaust restrictions. Exhaust restrictions will result in poor
performance at idle.
Add 12.7 cm (5 in.) for XL models to the listed outboard mounting heights.
The mounting height of the outboard must not exceed 63.5 cm (25 in.) for L models, 76 cm (30 in.)
for XL models. Mounting the outboard higher may cause damage to the gearcase components.
a
10 20 30 40
f
NOTICE
200/225 OPTIMAX DTS
c
d
50 60 70 80
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b