Pegasus R-9/2800-200 Instruction Manual

4-CYCLE MODEL ENGINES
R-9/2800-200
AUTHENTIC SCALE MARK I SERIES
SCALE 9 CYLINDER (200 CC) RADIAL ENGINE
OPERATING, MAINTANCE AND SAFETY MANUAL
VOLUME 1 REVISION 4

CAUTION before attempting to mount and run
your engine on a test stand or aircraft, this manual should be
completely read and understood. If you have any questions,
concerns or things that you do not fully understand, you should
contact the Customer Services Department at PEGASUS AIRCRAFT
ENGINES, 1-888-898-7841 between the hours of 9:00 AM and 5:00
PM, EST, Monday through Friday. You can also send an email to
[e-mail].
CONGRATULATIONS, you have purchased one of the finest
miniature radial engine available on the market today! The
PEGASUS AIRCRAFT ENGINES R-9/2800-200 radial engine is
an almost exact replica of the front half of the full scale Pratt &
Whitney R2800 TWIN WASP radial engine. The engine is a total of
200cc in 9 cylinders and is 1/5th scale.
All PEGASUS AIRCRAFT ENGINES are CNC machined from high
quality, alloy bar stocks and have unsurpassed fit and finish. Unlike
other engines offered on the market today, the PEGASUS
AIRCRAFT ENGINES line of engines are completely assembled in
the USA using the highest quality materials and components
available.
PEGASUS AIRCRAFT ENGINES has developed one of the best
customer support programs offered by any engine manufacturer.
When you call or email our Customer Services, you will be in contact
with an expert on your particular engine not a lay person hired to
answer the phone. What ever problem you are experiencing or
question you may have will be addressed quickly and expertly by
one of PEGASUS AIRCRAFT ENGINES qualified representatives.

WARNING this miniature engine is not a toy but
rather a power source for the propulsion of an R/C aircraft. It is
expressly forbidden to use this engine to power any manned or
human carrying aircraft or vehicle. Any misuse, abuse, incorrect
handling or crash damage can cause the engine to malfunction.
Such malfunctions could result in injuries to you and bystanders as
well as damage to the aircraft and property. In any of the above
mentioned situations, the engine should be returned to the factory
or an authorized repair station for evaluation and repair before
reinstalling on the aircraft for continued use.
Minimum age for operating this engine is 14 years of age. Young
people should be accompanied by an older, more experienced R/C
modeler.
Miniature engines have all the trappings of the full scale engines
such as becoming extremely hot when operating or after shut
down. First, second and third degree burns are a real possibility.
Fuel, oil fluids and exhaust emissions can be considered toxic. You
should understand the hazards of gasoline and be cautious not to
allow it to come into contact your eyes. Do not ingest even the
smallest amount. Washing your hands after contact with model
fuel is strongly suggested. Always keep fuel out of the reach of
children and pets.
Propellers are extremely dangerous whether they are full scale or
model. Caution should be exercised at all times when the engine
is running.

RIGGING YOUR ENGINE
FUEL SYSTEM: To rig your R9 engine for fuel, first you will need a
32 to 50 ounce fuel tank. The fuel tank must be adapted to use
gasoline. Your local hobby dealer can sell you the necessary parts
to accomplish this. All fuel lines need to be Tygon flexible fuel
tubing or gasoline compatible equivalent. When rigging the fuel
lines, run a line from the pickup port on the fuel tank to the electric
fuel pump (end with hex). Next run a line from the fuel pump (flat
end) to the port on the side of the carburetor. The top port (on the
carburetor) is a vent that allows the diaphragm in the carburetor to
work. If using a fuel filter, make sure it is gasoline compatible and
install it between the fuel tank and the fuel pump. The vent line on
the fuel tank needs a large loop of line affixed to the top of the fuel
tank and then exit on the outside of the airplane. The large loop (on
top of the fuel tank) insures that the vent line will not leak fuel. No
pressure line is required. Ad a third line to the fuel tank with a
stopper on the end. This line is used to fill the tank with fuel.
The fuel pump should be powered by a 6 to 12 volt battery. 2000 to
5000 mAh NiCad, NMH or LiPo is recommended. If using the larger
mAh battery, the one battery can be used for both the fuel pump and
the CDI ignition system. It is recommended to have a separate
on/off switch for the fuel pump. This allows you to prime the engine
without the ignition being on.
IGNITION SYSTEM: When rigging the CDI ignition box to your
engine, start by determining which cylinder is #1 cylinder. Hold the
engine with the scale magneto facing straight up. The scale
magneto is the black part between the two scale distributors (round,
silver canisters) on the nose cone housing of the engine. With the
engine in this position, look at the bottom most cylinder of the 9
cylinders. This is #1 cylinder. The spark plug wires starts at #1
cylinder and progresses in a counter clockwise direction (when
looking at the front of the engine, propeller end).

Place #1 spark plug wire on #1 cylinder’s spark plug and #2 spark
plug wire on #2 cylinder’s spark plug (just to the right of #1 when
looking at the front of the engine). Continue this progression until
you have all spark plug wires installed.
Install the grounding leads that are sleeved to the spark plug wires
by first attaching the lead to the upper most screw on the intake
tube’s brass retainer ring.Next install the other end of the
grounding lead wire to the ground wire on the CDI ignition box. This
is a black wire protruding from the ignition box with a ring connector
affixed to the end of the wire. All nine grounding leads need to be
attached to the ring connector on the ignition box ground wire using
a small bolt, 2 washers, lock washer and nut. On later models, the
ignition box has a nine lead extension with bullet connectors for
greater ease of rigging.
The CDI ignition is powered by a 6 to 8.4 volt battery. 2000 to 5000
mAh NiCad, NMH or LiPo battery is recommended. As stated
above, one battery can be used if it is a high capacity battery (5000
mAh) for both the ignition and fuel pump (not to exceed 8.4 volt). If
using one battery, it is recommended to check the amount of charge
in the battery between flights. A separate switch (from the fuel
pump) is recommended for the ignition system. Also recommended
is transmitter operated switches (one for the ignition & one for the
fuel pump) that will allow you to kill the engine remotely in case of an
emergency. See diagram below for the engine’s suggested fuel and
ignition rigging in your airplane.

ENGINE COMPONENT RIGGING SCHEMATIC
The above schematic is a suggested way to rig the components of
your engine. It is situated to use a single battery (not to exceed 8.4
volts) for both the CDI ignition and the fuel pump. Separate
batteries can be used for the CDI ignition and the fuel pump if you
choose. The above schematic is a way of saving weight by using
only one battery. NOTE: Only one mechanical switch is shown to
operate the fuel pump and CDI ignition. Another mechanical switch
can be installed between the Y harness and the CDI ignition box to
allow you to turn off the ignition while priming the engine.
Also shown is the receiver battery. In the above schematic, the
Tach. is powered by the receiver battery as the Tach. draws very
little current. NOTE: Be careful not to cross polarity when plugging
in the various electrical connectors. Always check that the color
coded wires match up. The grey lead from the sensor cartridge to
the CDI ignition will only plug in one way.

STARTING THE PEGASUS RADIAL ENGINE
All radial engines have an inherent tendency to possibly become
hydraulically locked. This means that the 3 bottom cylinders can
become flooded with fuel and oil causing the engine not to turn
over. Before attempting to start the engine, always roll the engine
through several revolutions (making sure the ignition is turned off
before rotating). If the engine does not want to rotate past a
certain point, do not try to force it. At this time, you will need to
remove the spark plugs from the 3 bottom cylinders and rotate the
engine until all excess fuel and oil is pumped out the spark plug
hole. Reinstall the spark plugs and continue the starting procedure.
When the engine is cold, first be sure the Ignition switch is off, the
fuel pump is on and the choke is closed. Flip the prop
approximately 5 times. This will prime the engine with fuel. Next
with the choke in the open position, set the throttle to about ¼
throttle. Turn the ignition switch on and start the engine. To insure
that all cylinders are firing, you can use a temperature gun to check
the exhaust temperature near the cylinder head. All cylinders
should be similar in temperature and the engine running smoothly.
To start the engine when it is hot or warm, first turn the fuel pump
on and the ignition off, close the choke and flip the prop 2 or 3
times. Open the choke, turn the ignition on and set the throttle just
above idle to start the engine. Our test engines usually start with
one flip of the propeller blade.
OPERATING AND TUNING
Operating and tuning your PEGASUS AIRCRAFT ENGINES radial
engine is not difficult but requires attention to carburetor tuning,
propeller choice, periodic valve adjustment & lubrication, correct
(fresh) fuel and overall awareness of its general condition.

Fuel for your radial engine should be a high quality gasoline of at
least 91 octane. The recommended oil is Klotz KL-189 and should
be mixed 50:1 for break and normal use. Adding nitro methane or
methanol for any reason will not enhance the engine’s performance
but rather cause undue wear, overheating and the voiding of your
warranty.
Starting with the carburetor adjustments, both the high speed
and low speed needle valves are pre set at the factory for correct
fuel delivery under normal operating conditions (air temperature,
barometric pressure and elevation). The elevation of your location
is important to properly tuning your carburetor. The elevation of
the PEGASUS TECHNOLOGY factory is 188’ above sea level. You
can find out the elevation of your area by calling your local airport.
Depending on your location, minor adjustments may need to be
made but major adjustments are a mistake. Minor adjustments
usually consist of no more than 1/8 turn in either direction of the
low and high speed needles valves. If you loose your place (with
the needle valves) the low speed needle is 2 turns out (counter
clockwise) and the high speed needle is 6 turns out (counter
clockwise) from completely closed. This is the factory settings.
It is critical to insure that your linkage and servo throw do not allow
the throttle plate to move past center line (FULL OPEN POSITION)!!.
This could cause an unsafe loss of power and or stall of engine. It is
important to use a stiff linkage rod to prevent High G forces from
flexing the linkage rod into a position that could allow the throttle
plate to move past full open position!!
For the start up and initial break-in period of your engine, be sure
the fuel to oil ratio is 50:1. Run the engine at approximately 1/2
throttle for at least 4 tanks of fuel (32 oz or 1000 ml per tank).
During this period, vary the throttle up and down slightly. Run the
engine 5 to 10 minutes at a time letting it cool down between runs.
Do not try to idle the engine during the first 15 minutes of break-in
as doing so can cause an adverse and degenerating affect on the
cam, cam lobes and cam followers.

To properly adjust the engine after a break-in period of at least 1
US gallon of fuel, bring the engine to full throttle. Using a
tachometer, lean the engine (using the high speed needle) until it
turns its highest RPM (never more than 4200 RPM depending on
prop selection). Do not attempt to lean the engine to produce more
than 4200 RPM. The electronic ignition has a built in rev limiter
preset at 5100 RPM but this setting is only for safety purposes. It is
not meant to be the maximum RPM setting for the engine.
After the engine is turning the recommended RPM (without loosing
RPM), turn the high speed needle valve counter clockwise 1/8 turn.
This will insure the engine has sufficient fuel when the aircraft starts
accelerating forward and the prop loads by cutting through clean air
instead of cavitating the air when run in a static situation.
Once you have the high speed needle valve set and the break in
period is complete, the low speed needle valve can now be
adjusted. A common misconception is that the low speed needle
valve only affects the idle performance of the engine. In reality, the
low speed needle valve affects both the idle and mid range of the
engine. The high speed needle valve only affects peak power
settings. If the engine idles rough and is sluggish when the throttle
is advanced, the low speed needle valve needs to be leaned (turn
clockwise no more than 1/8 of a turn initially). Continue turning the
low speed needle clockwise in 1/16 turn increments until the engine
idles smoothly (app. 750 RPM) without trying to die and responds
fast and crisp to throttle advance. Between each adjustment, the
engine needs to be revved up to clear out excess fuel and oil.
At this point your engine is adjusted well enough to make the first
flight. Further “tweaking” of the high and low speed needles may
be necessary to get the ideal performance for your area. As the
seasons change, adjustments may be necessary to keep the engine

running at peak performance. In cold weather the air is denser thus
more fuel is needed and in hot weather, the opposite applies.
FRESH AIR INTAKE
When using an engine cowling, such as in the case of most WWII
fighter planes, a fresh air intake must be established on the outside
of the fuselage. This is necessary due to hot, contaminated air
inside the cowling. In testing we have found that the engine will
loose power and RPM if a fresh air source is not supplied to the
carburetor.
In fabricating a fresh air source for your engine, a plenum area
must be established just in front of the carburetor.
This consists of a box area that is considerably larger than the
carburetor’s intake throat. If a plenum area is not used, it will cause
the engine to loose power and RPM plus not respond well to throttle
increases.
Periodic maintenance and inspection is a must on this very
complex engine. Your radial engine should be inspected
periodically, approximately every 1 hour of run time, for loose
fasteners (bolts, nuts, screws, etc.). Checking the tightness of all
fasteners is a good ideal. Never over tighten any fastener. The
screws and nuts are very small (to obtain the scale look of the full
scale engine).
After 20 hours of run time, all the screws holding the cylinders to
the crankcase need to be replaced. These screws are sold in sets
and are not covered by the warranty as they are considered
expendable items. Go to the parts exploded view to find screws and

reference number to the parts list. When installing the cylinder hold
down screws always use a good grade of RED thread locker. For all
other screws use BLUE thread locker.
Re-lubricating the rocker arms should be done after every 10 hours
of run time. The rocker arms should be lubed with a high grade,
thick Molly lube.
Be cautious not to over lubing the rocker arms.
Too much lube will fill the pushrod tubes and hurt performance. A
good idea is to keep a log of run time on your engine. This will help
you know when to lube the rockers, adjust the rockers, inspect the
engine, etc. For your convenience, we have enclosed a log book
with your engine.
Also check for loose components by observing if any black residue is
omitting from between parts and components of the engine. This
black residue is finely ground metal mixed with oil that seeps from
between engine parts when the parts are loose or not sufficiently
tight. DO NOT run the engine until this situation is properly
addressed.
Valve Rocker adjustment is a critical part of your engine’s
performance. To ignore adjusting the rockers will lead to excessive
wear of the valve train and considerable loss of performance.
Adjusting the intake and exhaust rockers of each cylinder is
relatively easy to do but requires attention to finesse. If the rockers
are too loose the engine will loose performance and be hard to
start. If the rockers are too tight, it will cause excessive wear and
engine failure. The rockers need to be adjusted after the break in
period is completed and then every 10 hours there after.

To adjust the valves, start by removing the rocker covers and spark
plugs from the cylinder heads. While looking through the spark plug
hole, rotate the crankshaft until the piston comes to TDC (top dead
center) with both rocker arms in the horizontal position (both valves
closed). You will note that both rocker arms are slightly loose in
this position. This should be the combustion stroke where you can
rock the crankshaft side to side without the rockers moving. If the
rockers move immediately when the crankshaft is slightly rocked
either way, this is between the exhaust stroke and intake stroke.
This position should not be used to adjust the valves as it is easy to
make a mistake in this position.
Using a box end (closed end) 7mm wrench and a 2mm socket head
wrench (Allen wrench), loosen either of the rocker arms one at a
time. Completely adjust one rocker arm and retighten before
starting on the other. Either the exhaust side or intake side can be
adjusted first. The sequence does not matter.
The adjustment starts by loosening the adjuster screw’s lock nut
with a box end 7mm wrench while holding the adjuster screw in
place with a 2.5mm socket head wrench. The engine needs to be
completely cooled down to room temperature (app. 70°) before
starting the rocker adjustments. At this point, turn the adjuster
screw down (clockwise) until it just removes all slack from the
rocker. A feeler gage is not necessary for these adjustments. Be
cautious not to turn the adjuster screw too far as you only want the
slack removed. When you are satisfied that all the slack is
removed, tighten the lock nut while holding the adjuster screw
firmly in place with the Allen wrench. In some cases, tightening the
lock nut will change the setting you have established. If this occurs,
loosen the lock nut and start the procedure over until the setting
stays constant after the lock nut is tightened.

Use the same procedure to adjust the other rocker arm. With both
rocker arms adjusted, replace the rocker covers. Use blue thread
locker on the rocker cover’s screws. The rocker cover’s screws are
very small, do not over tighten them. Now proceed to adjust the
remaining valves using the same procedure described above.
Always do only one cylinder at a time.
ENGINE SPECIFICATIONS
Type
Radial, Gasoline, CDI Spark
Ignition
Scale
1/5th
Cylinders
9
Cooling
Air
Engine Displacement
12.2 cu. in. (200 cc)
Capacity Per Cylinder
1.33 cu. in. (22.22 cc)
Bore
29 mm
Stroke
32 mm
Power
15 hp
RPM Range
750-4200
Maximum RPM
4200
Engine Diameter
281 mm
Engine Length
275 mm
Weight w/o prop
13 lbs.
Fuel Usage
2.5 oz Per Minute
Recommended 2 blade
Propellers
32-14 Xoar (for break-in),
32-16 Xoar & 32-18 Xoar
Carburetor
1 Zama
Exhaust
Stainless Steel Collector Ring
w/smoke oil nipple (included)

SAFETY WARNINGS
*This model engine is not a toy! It is a sophisticated power
system to power model aircraft and should never be used for
any other purpose.
*Keep all loose items away from the propeller when the
engine is running.
*Never reach over the propeller to tune or adjust the engine while
the engine is running.
*Keep bystanders at least 30’ away while engine is running.
*When the engine is running, it becomes very hot. Never touch
the engine or exhaust as severe burns can result.
*Never operate engine with a damaged propeller. The propeller
can come apart or disintegrate and cause severe injury to
yourself and bystanders.
*Keep children and pets at least 30’ away while engine is running.
*Never be in front of the propeller while engine is running.
*Make sure the propeller is tight and secure before starting the
engine.
*Always have a helper hold the airplane securely in place before
starting the engine.
*Never throw a rag or other objects into the propeller to kill the
engine. Install engine kill switch on the transmitter or airplane
to kill the engine.

EXPLODED VIEWS

REPLACEMENT PARTS LIST
Parts numbers are for 1 each or 1 set as noted. For current
prices go to www.pegasusengine.com or call 1-888-898-7841.
ITEM
NUMBER
QTY.
PART
NUMBER
PART NAME
1
1
AS-21-901
CRANK SHAFT
2
1
AS-21-902
CRANKSHAFT SLEEVE
3
1
AS-21-903
NOSE CONE
4
1
AS-21-904
SCALE MAGNETO
5
2
AS-21-905
SCALE DISTRIBUTOR
6
1
AS-21-906
SCALE PROP CONTROLLER
7
1
AS-21-906A
SCALE PROP GOVERNOR,
ROLLER WHEEL
8
1
AS-21-907
SCALE OIL PUMP
9
1
AS-21-909
CAM
10
1
AS-21-910
CRANK SHAFT DRIVE GEAR
11
1
AS-21-911
CAM SECTION CRANKCASE
12
1
AS-21-912
CRANKCASE CORE
13
1
AS-21-913
INLET AND MOUNT
14
18
AS-21-914
CAM FOLLOWER
15
1
AS-21-915
MASTER ROD
16
8
AS-21-916
CONNECTING ROD
17
1
AS-21-917
LINK PIN RETAINING PLATE
18
18
AS-21-919
CAM FOLLWER BUSHING
19
1
AS-21-921
CRANKSHAFT COUNTER
WEIGHT
20
3
AS-21-922
COUNTERWEIGHT RIVETS
21
1
AS-21-924
EXHAUST COLLECTOR RING
22
1
AS-21-925
CAM DRIVE 35-10 GEAR_2 EA.
23
2
AS-21-929
FAN BOLT WASHER
24
9
AS-21-C00
CYLINDER HEAD, FRONT
25
9
AS-21-C02
PISTON ASSEMBLY
26
1
AS-21-C03
PROP HUB OUTER PLATE
27
1
AS-21-C04
PROP HUB-2 BLADE PROP
28
1
AS-21-C05
PROP HUB NUT