Top Flite Giant F4U Corsair User manual

™
READ THROUGH THIS MANUAL BEFORE STARTING CONSTRUCTION. IT CONTAINS IMPORTANT INSTRUCTIONS AND WARNINGS CONCERNING THE ASSEMBLY AND USE OF THIS MODEL.
Entire Contents © 2011 Hobbico®, Inc. TOPA0951 Mnl
WARRANTY
Top Flite®Model Manufacturing Co. guarantees this kit to be free from defects in both material and
workmanship at the date of purchase. This warranty does not cover any component parts damaged by use
or modification. In no case shall Top Flite’s liability exceed the original cost of the purchased kit.
Further, Top Flite reserves the right to change or modify this warranty without notice.
In that Top Flite has no control over the final assembly or material used for final assembly, no liability shall be
assumed nor accepted for any damage resulting from the use by the user of the final user-assembled
product. By the act of using the user-assembled product, the user accepts all resulting liability.
If the buyer is not prepared to accept the liability associated with the use of this product, the buyer is
advised to return this kit immediately in new and unused condition to the place of purchase.
To make a warranty claim send the
defective part or item to Hobby
Services at this address:
Include a letter stating your name, return shipping address, as much contact information as possible (daytime
telephone number, fax number, e-mail address), a detailed description of the problem and a photocopy of the
purchase receipt. Upon receipt of the package the problem will be evaluated as quickly as possible.
Hobby Services
3002 N. Apollo Dr. Suite 1
Champaign IL 61822 USA
SPECIFICATIONS
INSTRUCTION
MANUAL
Wingspan :62.5 in [1590mm]
Wing Area: 699 sq in [45.1 dm2]
Weight: 8.5– 9.5 lb
[3850– 4310 g]
Wing
Loading:
28– 31 oz/sq ft
[85–95 g/dm2]
Length: 50.5 in
[1285mm]
Radio: 5– 6 channel, 7– 8 servos
Engine: .61 cu in [10.0cc]
two-stroke glow,
.91 cu in [15.0cc]
four-stroke glow
[email protected]
Top Flite Models Champaign, IL
Ph: [phone], Ext. 5
Fax: [phone]

2
INTRODUCTION
Thank you for purchasing the Top Flite Gold Edition
1/8th-scale F4-U Corsair.60 ARF. In spite of the apparent
complication of the gull-wing design and the scale
appearance, you’ll find that the Corsair assembles
more quickly than expected. The flaps and ailerons
are pre-hinged and the outer flaps join to the inner
flaps with convenient tabs. Detailed instructions and
illustrations of various motor installations will get you
into the air in little time. Finally, the Corsair’s light
weight and generous wing area just about make it a
trainer. But we won’t tell if you won’t tell, and all the
spectators will think you’re a pro!
For the latest technical updates or manual corrections
to this model visit the Top Flite web site at www.top-flite.
com. Open the “GOLD EDITION ARFS” link on the
left side of the page and click on image of the Corsair
that appears. If there is new technical information or
changes, you’ll see an “Important! TECH NOTICE”
box on the upper left corner of the page. Click on the
Tech Notice box to read the info.
SCALE COMPETITION
The scale of this model is 1/8th (or 13% – 1/7.7 to be
precise). These figures were derived from comparing
the wingspan of this model to the wingspan of the full-
size.Though the Top Flite F4-U Corsair is an ARF and
may not have the same level of detail as an “all-out”
scratch-built competition model, it is a scale model
nonetheless and is therefore eligible to compete in the
Fun Scale class in AMA competition (we receive many
favorable reports of our ARFs in scale competition!). In
Fun Scale, the “builder of the model” rule does not apply.
To receive the five points for scale documentation, the
only proof required that a full size aircraft of this type in
this paint/markings scheme did exist is a single sheet
such as a kit box cover from a plastic model, a photo,
or a profile painting, etc. If a black-and-white photo is
used, other written documentation of color must be
provided. Contact the AMA for a rule book with full
details. See page 3 for the AMA contact information.
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Scale Competition . . . . . . . . . . . . . . . . . . . . . . . 2
AMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . 3
DECISIONSYOU MUST MAKE. . . . . . . . . . . . . . . 3
Engine Recommendations . . . . . . . . . . . . . . . . . 3
Retractable Landing Gear . . . . . . . . . . . . . . . . . 4
Radio Equipment . . . . . . . . . . . . . . . . . . . . . . . . 4
ADDITIONAL ITEMS REQUIRED . . . . . . . . . . . . . 4
Hardware and Accessories . . . . . . . . . . . . . . . . 4
Adhesives and Building Supplies . . . . . . . . . . . . 4
Optional Supplies and Tools. . . . . . . . . . . . . . . . 4
Covering Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 5
KIT INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . 5
ORDERING REPLACEMENT PARTS . . . . . . . . . . 5
KIT CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . 6
PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Prepare the Covering . . . . . . . . . . . . . . . . . . . . . 6
ASSEMBLETHEWING. . . . . . . . . . . . . . . . . . . . . 7
Install the Belly Pan & Air Intakes . . . . . . . . . . . 7
Hook Up the Flaps and Ailerons . . . . . . . . . . . . 9
Join the Wing Panels . . . . . . . . . . . . . . . . . . . . 10
Install the Retractable Landing Gear . . . . . . . . . . 11
Mount the Fixed Landing Gear. . . . . . . . . . . . . 14
ASSEMBLETHE FUSELAGE . . . . . . . . . . . . . . . 14
Install the Rudder . . . . . . . . . . . . . . . . . . . . . . . 14
Mount the Horizontal Stabilizer . . . . . . . . . . . . 16
Install the Elevators . . . . . . . . . . . . . . . . . . . . . 18
Install the Tail Gear Cover . . . . . . . . . . . . . . . . 18
Mount the Engine . . . . . . . . . . . . . . . . . . . . . . . 19
Install the Fuel Tank . . . . . . . . . . . . . . . . . . . . . 22
Mount the Cowl . . . . . . . . . . . . . . . . . . . . . . . . 22
Install the Replica Engine. . . . . . . . . . . . . . . . . 24
Final Radio/Retract Installation . . . . . . . . . . . . 25
Install the Cockpit. . . . . . . . . . . . . . . . . . . . . . . 26
Apply the Decals . . . . . . . . . . . . . . . . . . . . . . . 27
GETTHE MODEL READYTO FLY . . . . . . . . . . . 27
Balance the Model (C.G.). . . . . . . . . . . . . . . . . 27
Balance the Model Laterally. . . . . . . . . . . . . . . 28
PREFLIGHT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Check the Control Directions . . . . . . . . . . . . . . 28
Set the Control Throws. . . . . . . . . . . . . . . . . . . 28
Identify Your Model . . . . . . . . . . . . . . . . . . . . . . 29
Charge the Batteries . . . . . . . . . . . . . . . . . . . . 29
Balance Propellers . . . . . . . . . . . . . . . . . . . . . . 29
Ground Check . . . . . . . . . . . . . . . . . . . . . . . . . 29
Fuel Mixture Adjustments. . . . . . . . . . . . . . . . . 29
Range Check . . . . . . . . . . . . . . . . . . . . . . . . . . 30
ENGINE SAFETY PRECAUTIONS . . . . . . . . . . . 30
AMA SAFETY CODE (excerpts). . . . . . . . . . . . . 30
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Radio Control . . . . . . . . . . . . . . . . . . . . . . . . . . 30
CHECK LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
FLYING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
LANDING GEAR DIAGRAM . . . . . . . . . . . . . . . . 32
THROTTLE PUSHROD HOLETEMPLATE. . . . . 33
COWL HOLE TEMPLATE . . . . . . . . . . . . . . . . . . 35
TABLE OF CONTENTS

3
If you would like photos of a full-size F4-U for scale
documentation, or if you would like to study the photos
to add more scale details, photo packs are available from:
Bob’s Aircraft Documentation
3114 Yukon Ave Ph: [phone]
Costa Mesa, CA 92626 Fx: [phone]
e-mail: www.bobsairdoc.com
AMA
We urge you to join the AMA (Academy of Model
Aeronautics) and a local R/C club. The AMA is the
governing body of model aviation and membership is
required to fly at AMA clubs. Though joining the AMA
provides many benefits, one of the primary reasons
to join is liability protection. Coverage is not limited to
flying at contests or on the club field. It even applies
to flying at public demonstrations and air shows. Failure
to comply with the Safety Code (excerpts printed in
the back of the manual) may endanger insurance
coverage. Additionally, training programs and instructors
are available at AMA club sites to help you get started
the right way. There are over 2,500 AMA chartered
clubs across the country. Contact the AMA at the
address or toll-free phone number below.
Academy of Model Aeronautics
5151 East Memorial Drive
Muncie, IN 47302-9252
Ph. [phone]
Fx [phone]
Or via the Internet at: http://www.
modelaircraft.org
IMPORTANT!!! Two of the most important things you
can do to preserve the radio controlled aircraft hobby
are to avoid flying near full-scale aircraft and avoid
flying near or over groups of people.
SAFETY PRECAUTIONS
PROTECTYOUR MODEL,YOURSELF &
OTHERS.....FOLLOWTHESE IMPORTANT
SAFETY PRECAUTIONS
1. Your Top Flite F4-U Corsair ARF should not be
considered a toy, but rather a sophisticated, working
model that functions very much like a full-size
airplane. Because of its performance capabilities,
the Corsair, if not assembled and operated correctly,
could possibly cause injury to yourself or spectators
and damage to property.
2. You must assemble the model according to the
instructions. Do not alter or modify the model, as
doing so may result in an unsafe or unflyable model.
In a few cases the instructions may differ slightly from
the photos. In those instances the written instructions
should be considered as correct.
3. You must take time to build straight, true and strong.
4. You must use an R/C radio system that is in first-
class condition, and a correctly sized engine and
components (fuel tank, wheels, etc.) throughout the
building process.
5. You must correctly install all R/C and other
components so that the model operates correctly
on the ground and in the air.
6. You must check the operation of the model before
every flight to insure that all equipment is operating
and that the model has remained structurally sound.
Be sure to check clevises or other connectors often
and replace them if they show any signs of wear
or fatigue.
7. If you are not an experienced pilot or have not flown
this type of model before, we recommend that you
get the assistance of an experienced pilot in your R/C
club for your first flights. If you’re not a member of a
club, your local hobby shop has information about
clubs in your area whose membership includes
experienced pilots.
8. While this kit has been flight tested to exceed
normal use, if the plane will be used for extremely
high stress flying, or if engines larger than ones in
the recommended range are used, the modeler is
responsible for taking steps to reinforce the high
stress points and/or substituting hardware more
suitable for the increased stress.
9. WARNING: Some of the parts in this kit are made
of fiberglass, the fibers of which may cause eye,
skin and respiratory tract irritation. Never blow into
one of these parts to remove fiberglass dust, as
the dust will blow back into your eyes. Always wear
safety goggles, a particle mask and rubber gloves
when grinding, drilling and sanding fiberglass parts.
Vacuum the parts and the work area thoroughly after
working with fiberglass parts.
We, as the kit manufacturer, provide you with a top
quality, thoroughly tested kit and instructions, but
ultimately the quality and flyability of your finished
model depends on how you build it; therefore, we
cannot in any way guarantee the performance of
your completed model, and no representations are
expressed or implied as to the performance or safety
of your completed model.
Remember: Take your time and follow the
instructions to end up with a well-built model
that is straight and true.
DECISIONSYOU MUST MAKE
This is a partial list of items required to finish this
model that may require planning or decision making
before starting assembly. Order numbers are provided
in parentheses.
ENGINE RECOMMENDATIONS
As specified on the cover of this instruction manual, the
Corsair is designed for a .61 cu in [10.0cc] two-stroke
or .91 cu in [15.0cc] four-stroke glow engine. And the
Corsair has the lightest airframe and wing loading of
all the “Gold” ARFs to date, so there is definitely no
need to overpower this model.
If using the O.S.
®Max .65AX 2-stroke, the stock
muffler may be used, but the O.S. #744B muffler
extension (OSMG2582) or the Bisson Pitts-style muffler
(BISG4061) will be required. If using the O.S. Max .91S
II 4-stroke engine, an O.S. FS70-91 Exhaust Header
Pipe (OUT) (OSMG2625) is also required. If using
the O.S. .95V, the M11 in-cowl 80D header pipe was
also used (OSMG2568). Refer to the Engine Mounting
instructions starting on page 19 for more information
and illustrations.

4
For the O.S. .91 4-stroke a 15 ×6 propeller is usually the
standard, “go-to” prop. However, a Master Air Screw 14
×7 prop is a nice 3-blade option for static scale effect.
In the air, the 14 ×7 loads the engine a little more than
the 15 ×6 and the Corsair flies slightly slower, but as
long as the engine is needled correctly the 14 ×7 will
provide great performance.
RETRACTABLE LANDING GEAR
The Top Flite Corsair .60 ARF comes equipped with
5.0mm fixed landing gear wires, but Robart pneumatic
retracts may be used instead.
For Robart retractable landing gear the following items
are required:
❍615 100 Degree Rotating Mains (ROBQ1815)
❍188VR Standard Air Control Kit (ROBQ2302)
❍190 Air Line Quick Disconnects (ROBQ2395)
❍Great Planes®Wire Axle 2x3/16" (2)
(GPMQ4282)
❍Great Planes 3/16" wheel collars (GPMQ4308)
❍K&S 7/32" brass tubing (for wheel spacers for
included wheels) (K+SR5130)
An air pump will also be required to fill the onboard
air cylinder when you get to the field and it’s time to
fly. The Robart Hand Pump & Gauge (ROBQ2363)
may be used, but those who fly often usually prefer
an electric hobby/emergency air compressor with a
pressure gauge. A wide selection of 12V pumps should
be available at most automotive stores. Use air line
that came with the retracts to connect the filler valve
to the compressor.
RADIO EQUIPMENT
If flying the Corsair with fixed landing gear, a five-
channel radio with seven servos will be required;
2 ailerons, elevator, throttle, rudder and 2 flaps. If
installing retracts, six channels will be required with
an eighth servo.
For all flight control surfaces, servos with a minimum
of 50 oz. in. of torque (such as Futaba®9001—
FUTM0075) should be used. For the throttle and the
air control valve, any standard servo is suitable (such
as Futaba S3003—FUTM0031).
Note:The servo output torque recommendations are
the minimums. Higher-torque, ball bearing servos could
be used for durability and flight precision.
The following servo extensions and Y-harnesses were
also used:
❍(2) 24" [600mm] servo extensions for the
aileron servos (HCAM2721 for Futaba)
❍(2) 6" [150mm] servo extensions for connecting
the flaps and ailerons to the receiver
(HCAM2701 for Futaba)
❍(2) Futaba dual servo connectors for the flap
and aileron servos (FUTM4130)
❍A minimum 1,000mAh receiver battery is also
recommended.
ADDITIONAL ITEMS REQUIRED
HARDWARE AND ACCESSORIES
In addition to the items listed in the “DecisionsYou
Must Make” section, following is the list of hardware
and accessories used to finish the Corsair as illustrated
in this instruction manual. Order numbers are provided
in parentheses.
❍1/4" R/C foam rubber (HCAQ1000)
❍3' [900mm] standard silicone fuel tubing
(GPMQ4131)
❍1/2" [13mm] double-sided foam mounting tape
(GPMQ4440)
❍Ernst #124 Charge Receptacle (ERNM3001 for
Futaba)
❍Stick-on segmented lead weights (GPMQ4485)
❍Propeller and spare propellers suitable for your
engine
❍1/7-scale Military Pilot (GPMQ9117)
ADHESIVES AND BUILDING SUPPLIES
In addition to common hobby tools and household
tools, this is the “short list” of the most important items
required to build the Corsair. Great Planes Pro™ CA
and Epoxy glue are recommended.
❍1 oz. [30g] Thin Pro CA (GPMR6002)
❍1 oz. [30g] Medium Pro CA+ (GPMR6008)
❍CA applicator tips (HCAR3780)
❍CA Activator (2 oz. [57g] spray bottle
(GPMR6035), or 4 oz. [113g] aerosol
(GPMR634)
❍Pro 30-minute epoxy (GPMR6047)
❍Threadlocker thread locking cement
(GPMR6060)
❍#1 Hobby knife (HCAR0105)
❍#11 blades (5-pack; HCAR0211, 100-pack;
HCAR0311)
❍Drill bits: 1/16" [1.6mm], 5/64" [2.0mm], 3/32"
[2.4mm], 1/8" [3.2mm], 3/16" [4.8mm]
❍8-32 tap and drill set (GPMR8103)
❍Tap handle (GPMR8120)
❍Soldering iron or Hobby Heat™Micro Torch II
(HCAR0755)
❍Silver solder w/flux (STAR2000)
❍Denatured alcohol for epoxy cleanup
❍Rotary tool and cutting bits
❍Fine-point felt-tip pen (Top Flite®Panel Line
Pen—TOPQ2510)
OPTIONAL SUPPLIES ANDTOOLS
Here is a list of optional tools that are also mentioned
in the manual.
❍Epoxy brushes (6, GPMR8060)
❍Mixing sticks (50, GPMR8055)

5
❍Mixing cups (GPMR8056)
❍CA debonder (GPMR6039)
❍J&Z R/C-56 canopy glue (JOZR5007)
❍Dead Center™Engine Mount Hole Locator
(GPMR8130)
❍Curved-tip canopy scissors for trimming plastic
parts (HCAR0667)
❍Non-elastic string for stab alignment (such as K
& S #801 Kevlar thread or fishing Kevlar thread)
❍Masking tape (TOPR8018)
❍CG Machine™(GPMR2400)
❍Precision Magnetic Prop Balancer (TOPQ5700)
❍2 pkgs. Great Planes #2 × 3/8" [10mm] button-
head Allen screws (for mounting the canopy
and bottom fuselage cover; see page 19)
(GPMQ3120)
❍Precision, durable .050" ball wrench for button-
head Allen wrench (MIPR9000)
COVERING TOOLS
A covering iron will be required for tightening the
covering on the model after it is removed from the
box. Following are the covering tools recommended:
❍21st Century®sealing iron (COVR2700)
❍21st Century iron cover (COVR2702)
❍21st Century trim seal iron (COVR2750)
The Top Flite Corsair ARF is factory covered with Top
Flite MonoKote®film. Should repairs ever be required,
following is a list of colors used on this model and
order numbers for 6' [1.8m] rolls. (At some hobby
shops MonoKote can also be purchased by the foot.)
Flat insignia blue TOPQ0507
Flat dove gray TOPQ0511
Note: The stabilizer and wing incidences and engine
thrust angles have been factory-built into the Corsair.
However, some technically-minded modelers may
wish to check these measurements anyway. To view
this information, visit the web site at www.top-flite.com
and click on “Technical Data.” Due to manufacturing
tolerances which will have little or no effect on the
way the model will fly, there may be slight deviations
between your model and the published values.
KIT INSPECTION
Before starting to build, take an inventory of this kit
to make sure it is complete, and inspect the parts
to make sure they are of acceptable quality. If any
parts are missing or are not of acceptable quality, or if
you need assistance with assembly, contact Product
Support. When reporting defective or missing parts,
use the part names exactly as they are written in the
Kit Contents list on this page.
Top Flite Product Support
3002 N. Apollo Drive, Suite 1 Ph: [phone]
Champaign, IL 61822 Fx: [phone]
E-mail: airsupport@top-flite.com
ORDERING REPLACEMENT PARTS
To order replacement parts for the Top Flite Corsair
ARF, use the order numbers in the Replacement Parts
List that follows. Replacement parts are available only
as listed. Not all parts are available separately (an
aileron cannot be purchased separately, but is only
available with the wing kit). Replacement parts are not
available from Product Support, but can be purchased
from hobby shops or mail order/Internet order firms.
Hardware items (screws, nuts, bolts) are also available
from these outlets. If you need assistance locating a
dealer to purchase parts, visit www.top-flite.com
and click on “Where to Buy.” If this kit is missing parts,
contact Product Support.
Order No. Description
REPLACEMENT PARTS LIST
TOPA1830
TOPA1831
TOPA1832
TOPA1833
TOPA1834
TOPA1835
TOPA1836
TOPA1837
TOPA1838
TOPA1839
TOPA1840
TOPA1841
TOPA1842
Fuselage Corsair .61 ARF
Wing Corsair .61 ARF
Tail Surfaces Corsair .61 ARF
Canopy Corsair .61 ARF
Cowl Corsair .61 ARF
Belly Pan Corsair .61 ARF
Tail Cover Corsair .61 ARF
Decals Corsair .61 ARF
Landing Gear Corsair .61 ARF
Spinner Corsair .61 ARF
Tailwheel Wire Corsair .61 ARF
Cockpit Corsair .61 ARF
Landing Gear Block Corsair ARF

6
PREPARATION
PREPARE THE COVERING
During assembly there will be several occasions
where epoxy cleanup will be necessary. Instead of
wasting whole paper towels, stack three or four
paper towels on top of
each other and cut
them into small squares.
This will eliminate wast-
ing whole paper towels
and the little squares
are easier to use. For
epoxy clean up, damp-
en the squares with
denatured alcohol.
❏1. Carefully remove any masking tape used for
temporarily holding parts together during shipping.
Any remaining glue from the tape can be removed
with paper towel squares dampened with naphtha
(lighter fluid).
❏2. Cut the covering over the air exit holes in the
ends of the rudder and elevators.These air passages
will allow expanding air to vent during the process of
tightening the covering. This will also keep the covering
KIT CONTENTS
1. Fuselage
2. Cowl
3. Replica Engine
4. Propeller Hub
5. Torque Bar
6. Fixed Landing Gear Mount
7. Main Landing Gear Wires
8. Wheel Covers
9. Wheels
10. Engine Mount
11. Fuel Tank
12. Canopy
13. Belly Pan
14. Cockpit Kit
15. Elevator Joiner Wire
16. Tail Gear Cover
17. Tail Gear
18. Horizontal Stab & Elevators
19. Rudder
20. Rudder Torque Rod
21. Right Wing Panel
22. Left Wing Panel
23. Servo Mount Blocks
24. Wing Joiners
25. Air Intakes
26. Wing Dowels
1
6
2
4
9
10
11
21
12
22
13
23 23
19
20
14
24 24
15
25 25
16
26
17
18
8
7
3
5

7
from puffing outward on hot days when your Corsair
is sitting in the sun.
❏3. Take time now to shrink the covering over open
structure (elevators, rudder) and shrink and seal the
covering to the rest of the airframe over sheeting.
Covering not bonded to the wood underneath—even
if you don’t see any wrinkles now—may form wrinkles
later. The best way to get the covering down and tighten
any wrinkles is with a covering iron with a protective
covering sock—a 21st Century covering iron with a
protective cover sock is best. Set the dial on the 21st
Century iron to 350°F (this should provide a surface
temperature on the cover sock of approximately 320°F
– 330°F). The trick is to push down on the iron to bond
the covering to the wood, but where the sheeting is
soft, thin or unsupported it may bend inward, making
it difficult to shrink the covering. So where possible,
reach inside and push back on the sheeting. Where
this cannot be done, glide the iron lightly over the area.
If blisters/bubbles appear in the covering you may be
using too much heat or leaving the iron in one position
too long. Allow the area to cool and keep the iron
moving or lower the temperature. Note: This process
takes time. If you don’t feel like going over the entire
model all at once, do the center wing panel first and
the rest of the parts as needed. Note: A drop or two
of CA debonder on one of your paper towel squares
is great for cleaning the covering in any areas where
the pigmented adhesive from one color has bled onto
another color.
ASSEMBLETHE WING
INSTALLTHE BELLY PAN & AIR INTAKES
❏1. Test-fit, then use 30-minute epoxy to glue both
5/16" × 1-3/16" [8mm × 30mm] hardwood wing dowels
into the leading edge of the center wing panel with
1/4" [6mm] of both dowels protruding. Be certain to
wipe away any excess epoxy around the dowel before
it hardens.
❏2. Use medium-grit sandpaper to roughen the bottom
edges of the fiberglass belly pan so glue will adhere.
❏
3. Bolt the wing to the fuselage with the two 1/4-20 ×
2" [50mm] nylon wing bolts.Test-fit the belly pan to the
bottom of the wing and fuselage. Make any adjustments
necessary for a good fit. Use a fine-point felt-tip pen to
mark the edges of the belly pan onto the wing.
❏4. Use the tip of a pointed soldering iron to melt
through the covering 1/16" [1.6mm] inside the lines you
marked and peel away the covering. If you don’t have a
suitable soldering iron, you could cut the covering with
a sharp hobby blade, but obviously use great care NOT
to cut into the wood. Wipe away the ink lines with one
of your paper towel squares and denatured alcohol.

8
❏5. Glue the belly pan into position with 30-minute
epoxy—use care not to allow excess epoxy to
inadvertently glue the wing or belly pan to the fuselage.
❏6. With the wing mounted to the fuselage, hold the
left wing air intake up against the fuselage. Use a
fine-point felt-tip pen to mark where to trim the intake
for a perfect fit.
❏
7. Trim and fit the intake as necessary until it fits well.
❏8. Holding the intake in position, use a fine-point
felt-tip pen to mark its outline onto the top and bottom
of the wing.
❏9. Use a small pin to perforate the covering just
inside the outlines.
❏10. Use one of your paper towel squares and
denatured alcohol to wipe the ink lines from the wing.
Hold the intake into position and carefully glue it to
the wing with thin CA. Or, use J&Z R/C 56 canopy
glue instead. If using canopy glue, hold the intake to
the wing with masking tape until the glue dries. Hint:
If using CA, first use CA accelerator to lightly “prime”
the underside of the intake where it contacts the wing.
Allow the accelerator to dry for a few seconds, then
glue in place.
❏11. Trim, fit and glue the right intake into position
the same way.

9
HOOK UPTHE FLAPS AND AILERONS
Center Panel
Outer Panels
Before hooking up the flaps and ailerons note the
orientation of the servo hatch covers in the bottom
of the wing panels.
❏1. Install the rubber grommets and eyelets into the
servos. Hold two hardwood servo mount blocks to
your flap servo with thin cardstock or 1/32" [.8mm]
plywood spacers under the servo and between the
blocks and the servo to provide the necessary spacing
for proper vibration isolation. Drill 1/16" [1.6mm] holes
into the servo mount blocks for the servo mounting
screws and mount the servo to the blocks with the
screws that came with the servos.
❏2. Mount the other flap servo to another set of mount
blocks the same way.
❏3. Temporarily place the servo arms on the flap
servos to aid in centering them in the hatch openings.
Use 30-minute epoxy to securely glue the mount blocks
to the hatch covers with the arms centered both fore
and aft and side-to-side in the openings—be certain
to apply epoxy to the ends of the blocks and to the
hatch for a secure bond.
❏4. Cut two 6" [150mm]
pushrods to a length of 4-1/4"
[108mm] by cutting the un-
threaded end. Read the
ExpertTip that follows about
soldering, then solder a clevis
onto one end of each pushrod.
While you have your soldering
equipment out, go ahead and
cut the aileron pushrods to a
length of 3-1/4" [83mm] and
solder the clevises to them
as well.
HOW TO SOLDER
1. Use denatured alcohol or other solvent to
thoroughly clean the pushrod. Roughen the end of
the pushrod with coarse sandpaper where it is to
be soldered.
2. Apply a few drops of soldering flux to the end of
the pushrod, and then use a soldering iron or a torch
to heat it. “Tin” the heated area with silver solder
by applying the solder to the end. The heat of the
pushrod should melt the solder – not the flame of
the torch or soldering iron – thus allowing the solder
to flow. The end of the wire should be coated with
solder all the way around.
3. Place the clevis on the end of the pushrod. Add
another drop of flux, then heat and add solder. The
same as before, the heat of the parts being soldered
should melt the solder, thus allowing it to flow. Allow
the joint to cool naturally without being disturbed.
Avoid excess blobs, but make certain the joint is
thoroughly soldered.The solder should be shiny, not
rough. If necessary, reheat the joint and allow to cool.
4. Immediately after the solder has solidified, but
while it is still hot, use a cloth to quickly wipe off
the flux before it hardens. Important: After the joint
cools, coat the joint with oil to prevent rust. Note: Do
not use the acid flux that comes with silver solder
for electrical soldering.
This is what a properly soldered clevis looks
like – shiny solder with good flow, no blobs and
flux removed.
Aileron Pushrod
3-1/4" [83 mm]
4-1/4" [108 mm]
Flap
Pushrod

10
❏
5. Hook up the left flap using the hardware shown—
using care not to drill through the top of the wing, drill
1/16" [1.6mm] holes for the #2 × 1/2" [13mm] Phillips
screws, positioning the base of the horn 5/16" [8mm]
from the wing trailing edge as shown. Use #2 washer-
head Phillips screws for mounting the hatch.
❏6. IMPORTANT! Temporarily remove the horn
mounting screws from the flap, add a few drops of
thin CA to the holes, allow to harden, and then remount
the horn. Perform the same procedure for the hatch
screws too.
You can set up the flap throw now, or wait until the
model is finished and you are programming the radio.
❏7. If you do wish to set up the flaps now, guide the
flap servo wire through the ribs and the hole in the
top of the wing and temporarily connect the flap servo
to the appropriate channel in your receiver (a servo
extension may be useful here). Connect a switch and
a battery to the receiver and retrieve your transmitter
so you can power the servo.
❏8. Turn on your transmitter and receiver. Start by
setting the ATVs on your flap channel in your transmitter
to 50% at both ends (up/down).This should be a good
starting point for the correct flap throw. With the flap
switch in the retracted position (flaps up), the outer
hole in the servo arm should be slightly above the
hatch. With the switch in the extended position (flaps
down), the outer hole in the servo arm should be
slightly below the hatch. Once you have the servo arm
correctly positioned, cut off the unused arms. Caution:
Don’t forget to install the servo arm screw.
❏9. Mount the hatch to the wing and connect up the
pushrod to the outer hole in the servo arm. Adjust the
length of the pushrod and fine tune the ATVs to achieve
the correct flap throw as illustrated on page 29.
❏10. Hook up the right flap the same way. This
time, connect both servos to the flap channel using a
Y-connector and do not adjust the ATVs. Simply adjust
the length of the right flap pushrod to duplicate the
throw of the left flap.
❏
11. Hook up the ailerons the same as the flaps with
the following exception:When the servo is centered, the
servo arm should be set approximately ten degrees
forward.This will provide symmetrical aileron throw even
though the servo rotates the same in both directions.
JOINTHE WING PANELS
❏1. Securely glue together two sets of two plywood
wing joiners to make two complete joiners.

11
❏
2. Glue the 1/8" [3.2mm] plastic alignment pins
halfway into both ends of the center panel.
❏3. Test fit, but do not glue one, then the other outer
panel to the inner panel with the wing joiners. Make
any adjustments necessary for a good fit.
❏4. Install two 24" [610mm] servo extension wires
through one side, then the other side of the center
panel that will connect to the aileron servo wires when
the wings are permanently joined (it will be helpful
to temporarily remove the flap servo hatches to help
guide the wires).
❏5. Cut one of the included pieces of shrink tubing
in half. Use the tubing to connect the aileron servo
wire coming out of one of the panels to the servo
extension wire coming from the respective end of the
center panel. Carefully shrink the tubing with a hobby
torch or a heat gun.
❏6. Gather everything required to glue together the
panels: 30-minute epoxy, mixing sticks and cups, epoxy
brushes, masking tape and your paper towel squares
and denatured alcohol for epoxy clean up.
Note: Join only one outer panel to the center panel
at a time with one batch of epoxy—do not attempt to
join both outer panels at the same time or with the
same batch. Otherwise, you may run out of working
time before the epoxy begins to harden.
❏7. Mix approximately 3/4 oz. of 30-minute epoxy.
Liberally apply epoxy in the spar “pocket” in the outer
wing panel and all the way around the outer half of one
of the joiners. Insert the joiner into the outer panel, and
then coat the pocket in the inner panel and all other
joining surfaces with epoxy. Proceeding quickly, join
the panels and proceed to the next step. IMPORTANT:
Don’t forget to key the tab in the outer flap into the
slot in the middle flap.
❏8. Use paper towel squares dampened with
denatured alcohol to wipe away epoxy as it squeezes
from the wing when you press the panels together.
Use several strips of masking tape to tightly tape the
panels together. As the epoxy hardens and continues
to leak from the seam, one strip at a time, remove
the tape, wipe away the epoxy, and then immediately
replace it with another strip to keep the wing tightly
clamped. Continue to monitor the wing, wiping away
leaking epoxy and making sure the gap remains tight.
❏9. After the epoxy has hardened, carefully remove all
the tape. If the epoxy is hard but has not yet fully cured,
there is still time to clean up any remaining epoxy with
paper towel squares dampened with denatured alcohol.
❏10. Join the other panel the same way – don’t forget
first to connect the other aileron servo wire to the other
extension in the wing and secure the connection with
heat shrink tubing. After all the epoxy has been cleaned
up, use a covering iron to re bond any covering that
may have pulled away when removing the tape.
INSTALLTHE RETRACTABLE LANDING GEAR
If not mounting retractable landing gear, skip to “Mount
the Fixed Landing Gear” on page 14.
❏1. Note: There are no flat spots on the ends of the
struts for the set screws in the toothed cam gear. It is
highly recommended that you remove the struts and
grind at least one flat spot for one of the set screws
in the collar. Otherwise, the strut may slip in the collar
on the gear. When reattaching the gear to the strut,
threadlocker should also be used on the threads of
the set screws.

12
❏2. Identify the right and left retract—the wheels
are mounted on the outside of each strut, and as the
gear retracts, the fronts of the wheels rotate outward,
toward the respective wing tips.
❏3. Position the gear on the rails, centering the strut
in the wheel well. Mark the screw hole locations.
❏4. Drill 3/32" [2.4mm] holes through the rails at
each mark.
❏5. Temporarily mount each gear with four #4 × 1/2"
[12mm] Phillips screws. Center one of the wheels in
the wheel well. Use a felt-tip pen to mark the strut
approximately 1/8" [3mm] past where it crosses the
hole in the wheel.
❏6. Remove the gear and use a rotary tool with a
fiber-reinforced cutoff wheel to cut the strut at the mark.
While the gear is out, add a few drops of thin CA to
the screw holes in the rails to harden the “threads.”
❏7. If using Robart retracts
and the included Top Flite foam
wheels, cut two 1/2" [14mm]
bushings from 7/32" K&S
brass tubing (not included)
and use a small metal file,
sandpaper or a hobby knife to de-burr the ends of the
bushings. The bushings will be a tight fit, but press
them into each Top Flite wheel.
❏
8. Place one of your wheels onto an axle with a
wheel collar. Use a fine-point felt-tip pen to mark the
end of the collar on the axle. Use a rotary tool with a
fiber-reinforced cutoff wheel to cut the axle at the mark.
❏
9. File a flat spot
near the end of the
axle for the screw
in the wheel collar.
❏10.Temporarily mount the wheel to the axle with the
wheel collar and temporarily mount the axle to the strut.
❏11. Retract the gear into the wheel well. Adjust the
position of the axle on the strut so the wheel will be
centered in the well. Partially tighten the screw in the
axle, temporarily locking it to the strut.
❏12. Extend the gear.Twist the wheel and axle on the
strut so the wheel will be aimed straight ahead, or have

13
approximately 1 degree of toe-in. Securely tighten the
screw in the axle onto the strut, then partially loosen
and tighten again so the screw will mark the location
where it has bottomed out on the strut. This will identify
the precise location where a flat spot is to be ground
into the strut.
❏13. Remove the axle from the strut and remove the
retract from the wing. Grind a flat spot into the strut at
the mark left by the screw in the previous step.
❏14. Tighten the axle onto the strut. Mount the gear
to the rail. View the wheel to see if the alignment is
correct. If necessary, adjust the flat spot until the wheel
is straight ahead, or has a small amount of toe-in.
❏15. Once the wheel and axle are properly aligned,
add a drop of threadlocker to the threads on the axle
screw, then securely tighten the screw in the axle
locking the axle to the strut. Also use a small drop
of threadlocker on the screw that secures the collar
mounting the wheel to the axle.
❏16. For the final time, remove the retract from the
wing. Cut two 15" [380mm] lines from the pneumatic
line included with your retracts. Guide one of the lines
through the hole in the side of the rib under the flap
servo hatch out through the hole in the back of the
retract cavity (top photo at left). Guide the other line
in through the hole in the front of the flap servo hatch
(middle photo at left) and out through the holes in
the sides of the ribs on the side of the retract cavity
(bottom photo at left). It can be a little tedious to get
the lines through all the ribs and passages, but a pair
of hemostats and a piece of leftover pushrod wire with
a small “L” bent on the end makes fishing the air lines
through pretty easy.
❏17. Connect the lines to the fittings on the air cylinder
on the retract. Using care not to kink or pinch the air
lines, mount the gear to the rails with all four screws.
Snap the wheel cover into the rim on the outside of
the wheel as shown on page 14.
❏18. Guide the other ends of the air lines through the
ribs in the center wing panel and out the hole in the top.
❏19. Refering to the diagram on page 32, use the
T-fittings to connect both “up” lines and both “down”
lines to each other and connect another length of line
to each T-fitting with a quick-disconnect.

14
MOUNTTHE FIXED LANDING GEAR
❏1. Position the fixed landing gear mounts on the rails
in the wing. Drill 3/32" [2.4mm] holes through the rails
using the holes in the mounts as guides.
❏2. Enlarge the holes in all four nylon landing gear
straps with a 1/8" [3.2mm] drill. Insert the main landing
gear wires into the landing gear mount blocks, then
secure them with the straps and #4 × 1/2" [12mm]
Phillips screws. Note:The “axle” part of the gear wires
face outward—toward the respective wing tips.
❏3. Temporarily mount each block assembly to the
rails with four #4 × 5/8" [16mm] Phillips screws. Remove
the screws, harden the holes with a few drops of thin
CA, allow to harden, then remount the blocks.
❏4. Mount each wheel with wheel collars on both
sides and 3mm set screws with a drop of threadlocker.
Note the cutout in each wheel to accommodate the
hex key wrench.
❏5. Snap the wheel
covers into the wheels—
they snap on “hard.”
Make certain the outer
edge of the cover fits all
the way down around the
inside of the wheel so
that they will be securely
locked into position. (Also
note the small hole in the
other side of the wheel
for “popping out” the wheel cover with a small piece
of wire.)
ASSEMBLETHE FUSELAGE
INSTALLTHE RUDDER
Do not use any glue in the following steps until
instructed to do so.
❏1. Use coarse sandpaper to roughen the arm portion
of the rudder torque rod wire where it goes into the
rudder. Fit the torque rod down through the hole in the
fuselage at the base of the vertical stabilizer and into
the hinge bearing inside.
❏2. Stick a small T-pin through the middle of two CA
hinges. Insert the hinges into the rudder, then fit the
rudder to the vertical stab and the torque rod.
Refer to this photo for the following two steps.

15
❏3. Enlarge the outer hole in one of the plastic
steering arms with a 3/32" [2.4mm] drill. Mount a
2-56 threaded ball link ball to the outer hole in that
arm with a 2-56 lock nut.
❏4. Assemble the tail gear assembly with the parts
illustrated in the photo. Use a drop of threadlocker
on the 3mm set screw in the collar and on the 3mm
socket-head cap screw (SHCS) in the steering arm.
❏5. Position the tail gear assembly, then mark the
mounting holes in the tail gear mount onto the plywood
mounting plate. Remove the assembly and drill 1/16"
[1.6mm] holes through the plate at the marks.
❏6. Mount the tail gear assembly with three #2 ×
3/8" [9.5mm] Phillips screws. Temporarily remove the
screws, add a drop or two of thin CA to each hole, allow
to harden, and then remount the assembly.
❏
7. Cut a 36" [910mm] pushrod to a length of 24"
[610mm]. Securely thread a nylon ball link about 12
full turns onto the pushrod and snap the ball link onto
the ball link ball on the rudder arm.
❏8. Guide the pushrod through the screw-lock on
the tail gear arm and down through the rudder guide
tube in the fuselage. Mount the rudder steering arm to
the rudder torque rod, tightening it down with a 3mm
SHCS. Holding the rudder and tailwheel wire centered,
tighten the pushrod to the screw-lock connector on the
tail gear arm with a 4-40 × 1/8" [3.2mm] SHCS. Move
the pushrod back and forth to make sure everything
operates smoothly. Make any adjustments necessary.
❏9. Temporarily fit your rudder servo into the servo
tray with a servo arm, but don’t mount it with screws
yet. With the rudder servo arm centered, center the
rudder and mark the pushrod where it crosses the
holes in the servo arm.
❏10. Disconnect the rudder steering arm from the
rudder torque rod. Make a sharp, 90-degree bend in
the rudder pushrod at the mark made in the previous
step. Fit a FasLink over the pushrod, and then cut the
pushrod 1/16" [1.6mm] from the connector.
❏11. Remove the rudder from the vertical stabilizer.
Apply 30-minute epoxy in the torque rod hole in the
rudder and rejoin the rudder to the vertical stabilizer. Be
certain the rudder is positioned vertically so it moves
smoothly. Remove the T-pins from the rudder hinges
and add at least eight drops of thin CA to both sides
of both hinges to permanently hinge the rudder—be
certain to wait between drops for the hinge to absorb
the CA so it does not run into the hinge gap.

16
❏12. For the final time, securely connect the rudder
steering arm to the rudder torque rod using a drop of
threadlocker on the 3mm SHCS.
❏13. If necessary, rotate the rudder pushrod so the “L”
bend in the front of the pushrod is vertical and will fit
correctly into the rudder servo arm. Enlarge the holes
in the servo arm with a #47 (.076" [1.9mm]) drill, then
mount the pushrod to the outer hole. On the back end,
center the axle on the tail gear, and lock the pushrod
to the connector by tightening the 4-40 screw with a
drop of threadlocker on the threads.
MOUNTTHE HORIZONTAL
STABILIZER (STAB)
Gluing in the stab requires a bit of prep work that will
result in an accurately aligned stab and a plane that
flies straight-and-true.
❏1. Same as was done with the rudder torque rod,
use coarse sandpaper to roughen the “arm” portions
of the elevator joiner wire. Then, temporarily slide the
stab into position with the joiner.
A
A = A'
A'
❏2. Laterally center the trailing edge of the stab in the
fuselage by taking accurate measurements on both
sides of the trailing edge.
❏
3. Once the stab has been centered laterally, insert
pins into the TE tightly against both sides of the fuselage
so the stab will remain centered.
❏4. Stick a T-pin into the bottom of the fuselage
centered over the bottom stringer at the firewall.Tie a
loop in one end of an approximately 48" [1.2m] piece
of non-elastic line and loop it over the T-pin. Fold a
piece of masking tape over the other end of the line
and mark a line on it.

17
B = B' B
B'
❏5. Hold the tape on the line to one side of the stab,
then swing it over to the same location on the other
side of the stab to check the rotational alignment. Slide
the tape along the line and rotate the stab until it is
rotationally centered.
❏6.Tack-glue the plywood straight-edge supports to
the inner edges of the wing saddle where shown—be
certain that both supports are positioned in the same
location along the wing saddle by aligning the front
edge of the supports with the aft edge of the notch as
shown. Place a straightedge into the supports across
the bottom of the stab saddle.
❏
7. Finally, view the model from behind, making sure
the stab is parallel with the straightedge. If necessary,
place an ounce or so of weight over the high side of
the stab to get it aligned horizontally.
There’s no way around it. The next step will get
messy with epoxy, so have plenty of paper towel
squares and denatured alcohol on hand for cleanup.
Do not use 5-minute epoxy for this step!
❏8. Once you have the stab aligned, remove the T-pins
and slide the stab part way out. Mix approximately 1/2
oz. of 30-minute epoxy. Use a piece of wire or a small
dowel to apply epoxy to the exposed balsa all the way
around the top and bottom of the stab. Then, slide it
partway through the other way and apply more epoxy
to the exposed balsa all the way around the other side.
Slide the stab back into position and use your finger
or a piece of balsa to work the epoxy thoroughly into
the joint all the way around both sides. Stick the T-pins
back into the trailing edge of the stab, use the pin and
string to realign the stab rotationally and make sure
the stab is aligned horizontally. Continuing to check the
stab alignment as you proceed, wipe away epoxy with
your paper towel squares dampened with denatured
alcohol. Once the stab is finally aligned and all the
epoxy has been cleaned, leave the model alone until
the epoxy has hardened.

18
❏9. Same as after the wing panels were joined, if you
can catch the epoxy after it has hardened but before it
has fully cured, you may still be able to clean off any
remaining epoxy with more paper towel squares and
denatured alcohol.
INSTALLTHE ELEVATORS
❏1. Same as the rudder, insert a T-pin through the
middle of six CA hinges, then test fit the elevators to
the stab and the joiner wire. View the elevators from
the rear and make certain they align with each other.
If necessary, remove the elevators and use two pair
of pliers to bend the torque rod arms so the elevators
will align.
❏
2. Move the elevators up and down to make sure you
are getting the full, high-rate elevator throw specified
on page 29. If the root end of one of the elevators
interferes with the fuselage side, the elevators may
not be centered laterally. Shift the elevators with the
joiner rod to one side or the other to get them centered.
❏3. Once you understand how to align the elevators,
remove them from the stab, add 30-minute epoxy
into the holes for the joiner wire, rejoin the elevators
to the stab, and remove the T-pins from the hinges.
Permanently join the elevators by applying thin CA
to the hinges.
❏4. After the epoxy on the joiner wire has hardened,
cut a 36" [910mm] pushrod to a length of 30" [760mm].
Thread a nylon clevis onto the pushrod approximately
twenty full turns. Same as was done for the rudder
pushrod, bend and cut the pushrod to the correct
length to fit the elevator servo with a 90-degree
pushrod connector. Connect the clevis to the bottom
hole (farthest from the elevator) in the control horn
with a silicone retainer around the clevis.
INSTALLTHETAIL GEAR COVER
❏
1. Glue both hardwood blocks into position on the tail
gear mount plate where shown—with the front of the
blocks approximately 1/4" [6mm] back from the former.
❏
2. Holding the fiberglass cover in position, use a
pencil to mark the center of the block onto the cover,
then mark four more lines every 2-3/8" [60mm] behind
the first. Repeat the procedure for the other side of
the cover.

19
❏3. Drill 3/32" [2.4mm] holes through the cover
precisely 1/4" [6.4mm] up from the edge of the cover
at the front marks and precisely 1/8" [3.2mm] up from
the edge at the rest of the marks. The best way is first
to dimple the surface with a sharp 1/16" [1.6mm] drill,
and then drill the 3/32" holes while holding a wood
block to the back of the cover.
❏4. Holding the cover in position, use the middle
hole in one side of the cover to drill a 1/16" [1.6mm]
hole through the rail. Mount the cover with a #2 × 3/8"
[9.5mm] Phillips screw. Perform the same procedure
for the same hole on the other side. Then, alternating
sides, continue to drill the rest of the holes and install
the screws one at a time. Hint: Run the drill in and
out of the holes in the front blocks several times to
slightly enlarge the holes, or use a 5/64" [2.0mm]
drill for those holes. This is because the hardwood
that the blocks are made from grabs the screws
much harder than the rail for the rest of the screws.
Optional: Instead of using Phillips screws, use #2 ×
3/8" [9.5mm] button-head Allen screws (GPMQ3120,
not included). These Allen screws have a smaller
head for a better, more-finished appearance, but
require a high-quality .050" Allen wrench so the
heads do not strip out. A suitable wrench is the MIP
Thorp hex driver wrench (MIPR9000).
MOUNTTHE ENGINE
Although the O.S. .91 4-stroke engine is illustrated
in most of the photos,unless noted otherwise,the
mounting instructions apply to all engines.
❏1. Temporarily fit together the two halves of the
included motor mount with four 8-32 × 1" [25mm] SHCS,
#8 lock washers, #8 flat washers and 8-32 blind nuts
placed backwards on the screws, but leave the screws
loose enough so you can slide the halves in and out.
❏2. Adjust the mount to fit your engine and tighten
the screws so the halves will not slip. Use small clamps
to hold the engine to the mount with the drive washer
as close to 5-1/2" [140mm] as you can get, from the
base of the mount.

20
❏3. Use a Great Planes Dead Center hole locator to
mark the engine mounting bolt holes onto the mount.
❏4. Remove the engine from the mount. Use a drill
press or a hand drill to drill #29 (or 9/64" [3.6mm])
holes at the marks. Use an 8-32 tap to cut threads all
the way through the holes—turning the tap by hand is
not necessary—you can make the job easier simply
by chucking the tap in a cordless hand drill.
If you are using
the O.S. .91
four-stroke and
wish to mount
it the same way
as shown in the
manual, reverse
the carburetor so
the throttle arm
will be on the
left side of the
engine. Then,
it will be easier
to hook up the
throttle. (For the
O.S. .95, the carb arm should be on the right side
of the engine so the needle valve will come out the
top of the cowl if side-mounting the engine.)
❏5. Mount your engine to the mount with four 8-32 ×
1" [25mm] SHCS and #8 lock washers.
❏6. Remove the nuts and bolts holding the engine
mount halves together. Temporarily mount the muffler
to the engine. Hold the mount up to the firewall and
decide which way you are going to position the engine—
vertically, horizontally, a 45-degree angle or any other
angle around the circle inscribed on the firewall. Note
that the “X” marks on the firewall indicate the bolt hole
locations for the vertical or horizontal position. The
intersection of the horizontal and vertical lines and the
circle indicate the bolt hole locations for the 45-degree
position. The O.S. .91 four-stroke was mounted at a
45-degree angle positioning the muffler directly under
the fuselage (this also required a #72109600 O.S.
FS70-91 Exhaust Header Pipe (OUT – OSMG2625).)
The O.S. .65AX with the included O.S. muffler may also
be mounted at a 45-degree angle with the O.S. #744B
muffler extension (OSMG2582). This will position the
muffler just far enough away (1/8" [3mm]) from the
bottom of the fuselage.
The .65AX may also be mounted horizontally with a
Bisson Pitts-style muffler (BISG4061).
The O.S. .95V was side-mounted with the O.S. M11
in-cowl 80D exhaust header pipe (OSMG2568).
❏7. If mounting your engine in a different orientation,
make new marks around the circle inscribed on the
firewall where necessary. Drill precision 1/16" [1.6mm]
pilot holes at the proper marks, then enlarge the holes
with a 3/16" [4.8mm] drill.
❏8. Use one of the 8-32 SHCS and a #8 flat washer
to draw the 8-32 blind nuts into the back of the firewall
through the holes.