11
ENGINE INSTALLATION
The following instructions show the installation
of the engine. Because of the 1
½
-degrees of
right thrust is built into the engine support follow
the instructions so that the spinner lines up
correctly with the cowl.
The firewall is designed to handle a variety of 50
cc to 75 cc engines.
In this example a Brisson 4.2
ci is being installed.
In our last build, we installed a DL 50 and then a
Revolution 50.
(With the lighter engines, some added weight
may be required and all batteries should be
installed as far forward as possible)
The firewall is marked with cross lines for
vertical and horizontal. Note that the vertical line
is off center. This is designed to allow engine off
set while the propeller spinner ends up in center
of cowl face.
To make the marking job easier, make a template
of the engine mount, marking center and drawing
similar cross lines as marked on firewall.
Tape template to firewall, matching up the lines.
Drill the appropriate mounting holes.
Securely fasten engine to firewall. I used safety
nuts to ensure that the bolts will not come loose.
TEMPORARILY BALANCE THE
PLANE
Let’s take a break from the engine installation
and make sure the plane will properly balance. If
not, at this point you consider various options
such as moving the engine forward, moving
radio equipment, etc.
Temporarily assemble center portion of top wing.
Attach bottom and top wings.
Include all radio equipment such as receiver,
switches, batteries as well as fuel tank.
Attach hatch cover, cowl, spinner and prop.
The BALANCE POINT is between 2 ¼ and 2 ½
inches back of the leading edge of the TOP wing
at the TIP. This also works out to be about ¾
inch in front of the servo wire exit holes located
in the top wing center section.
ENGINE INSTALLATION - continued
