Installation - O.S. engine FSa-155-P Owner's Instruction Manual

It is suggested to use as heavy and rigid as possible engine mounting for highest performance and
safe running. Conventional wooden mounting beams should be of rigid hardwood and of at least
15mm or 5/8-in square section. Use at least 5mm steel screws, such as Allen type, with locknuts, for
bolting the engine to the bearers..
Make sure that the mounting beams are parallel and that their
top surfaces are in the same plane.
CORRECT
Side view
Rear view
Top surfaces are in the same plane.
How to fasten the mounting screws.
Hardwood mounting beams
5mm steel nuts
Spring washer or
lock washer
15mm min.
15mm min.
Radial motor mount (cast aluminum)
5mm
steel Allen screw
Top surfaces are not
in the same plane.
Re-align the surfaces
as necessary
14
Tighten second nut
firmlydown onto first nut.
Tighten this nut first.
Hardwood such as
cherry or maple.
Steel washer
5mm steel screw
Spring washer
15

INSTALLATION

INCORRECT
Opposite beam
Top surfaces are not in the
same plane.
Engine does not rest firmly.
● Make sure that these mounting beams are
accurately aligned and firmly integrated with
the airframe, reinforcing the adjacent
structure to absorb vibration. Use 4mm or
larger steel screws, preferably Allen type
hexagon socket head cap screws, with
washers and locknuts, for bolting the engine
to the bearers.
O.S. Radial Motor Mount
A special O.S. radial motor mount (Code
No.71904200) is available, as an optional
extra, for use where firewall type mounting is
required.