Propeller Rotation On Dual Installations - FNM HPEP 225 Installation Manual

EXTERNAL POWER STEERING
When boat speeds move past 112 KMH (70 MPH) or if additional steering backlash reduction is
desired, external power steering is recommended. This normally will include an external
tie bar mounted at the same general location of the power steering cylinders which are
generally attached at the top of the sterndrive's drive shaft housing. With this steering
system, no internal tie bar should be used. These steering cylinders can be attached either
inboard (between) or outboard of the sterndrives.
EXTERNAL POWER STEERING WITH LOW EXTERNAL TIE BAR
For the fastest boats (over 128 KMH - 80 MPH) or for the ultimate in steering backlash
reduction, use external power steering, BUT (where mechanically possible) with the
external tie bar mounted at the trim cylinder boss location (as previously described in Internal
and External Tie Bar). This system does not use an internal tie bar.
Important: MERCURY does not recommend the use of an external tie bar ONLY (no
internal tie bar) when using the internal power steering system. This can cause excessive
loads on the steering components on the drive connected to the internal power steering
system. These increased loads can damage the steering components, resulting in
increased play in the steering of the boat.

PROPELLER ROTATION ON DUAL INSTALLATIONS

Best all-around performance usually is obtained by installing engines so that propellers turn
outboard (looking at the stern → figure a)
a- Inboard Propeller Rotation
b- Outboard Propeller Rotation (Preferred)
c- RH Rotation
d- LH Rotation
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