Top Flite TOPA0905 - Manual (Page 30)

O.S. 1.60 Four-Stroke Engine
(Mounting hardware not included with kit.)
❏
1. Make stand-offs from dowels or a plywood plate
that will position the engine a distance of 6" [152mm]
from the firewall to the front of drive washer. Center
the engine so the engine will be centered in the cowl.
Make marks on the firewall for the location of the
mounting holes of the engine backplate.
❏
2. On each of the four marks drill a 7/32" [5.6mm]
hole. Install an 8-32 blind nut into each of the holes from
the back of the firewall. Install a #8 flat washer onto an
8-32 x 1" [25mm] socket head cap screw. Then, tighten
the screw into the blind nut, pulling it into the firewall.
❏
3. Mark the location where the throttle pushrod will
come through the firewall. (Note: Because the
carburetor is an up-draft carburetor, the fuel tank is
going to have to be relocated from the location for a
two-stroke engine to the lowest point in the fuselage.
Keep this in mind when determining the location for
the pushrod. The pushrod must not conflict with the
fuel tank).
❏
4. Install the throttle servo into the servo opening
in the fuselage and drill a 1/16" [1.6mm] hole through
each of the mounting holes. Remove the servo, and
then install and remove a servo mounting screw into
each hole. Apply a couple drops of thin CA into the
holes to harden the threads. When the glue has
cured permanently mount the servo.
❏
5. Install a brass screw lock
connector, nylon retainer ring and a
4-40 x 1/8" [3mm] socket head cap
screw onto the outer hole of the servo
arm and the throttle servo arm.
❏
6. Cut the threads from an .074 x
36" [914mm] threaded rod. Bend it to fit from the
throttle servo arm to the throttle arm. When bending
the wire be sure that you have clearance between
the pushrod and any of the engine/muffler
components. Metal contact may create radio
interference. Slide the pushrod wire into the brass
screw lock connectors. Then, tighten the 4-40 x 1/8"
[3mm] socket head cap screw against the throttle
pushrod wire. Cut off any excess wire.
Install the Fuel Tank for the
O.S. 1.60 Two-Stroke Engine
Follow these instructions for any engine that
does not have an up-draft carburetor.
❏
1. Assemble the fuel tank as shown in the sketch.
When tightening the center screw be sure not to over
tighten it. You just want it snug enough to pull the
rubber stopper tight against the tank.
❏
2. Install silicone fuel tubing (not supplied) onto the
aluminum tubes from the fuel tank. The line with the
fuel clunk will feed to the fuel inlet at the needle valve
and the other will attach to the pressure tap on the
muffler. If you choose to use some kind of an external
fuel valve follow the instructions with your particular
brand of fuel valve. You can also install a third line to
the tank and use it for filling the tank. The method you
use is your choice but make your decision before
moving onto the installation of the fuel tank.
❏
3. Install the tank into the fuselage with the neck
of the tank through the firewall.
FUEL TANK
S ILICONE
FUEL LINE
FUEL CLUNK
FUEL
PIPE
PRE SS URE
TAP TO
MUFFLER
TO NEEDLE
VALVE
FIREWALL
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