Great Planes Ultra Sport 1000 Kit - GPMA0425 - Manual (Page 5)

DECISIONS YOU MUST MAKE NOW
ENGINE, MOUNT, AND SPINNER SELECTION
The recommended engine size range is as follows:
90 - 1 50 cubic inch displacement 2-cycle
1.20 -1.60 cubic inch displacement 4-cycle
The complete "ENGINE APPLICATION TABLE" is printed on the fuselage plan A portion of that table is
reprinted here to help in your selection of engine, propeller, mount and spinner.
COMPONENTS RECOMMENDED FOR THE ULTRA SPORT 1000:
ENGINE PROP
OS 120 SURPASS SP* 16x8
SUPERTIGRE 2500 16x10
OS 120 SURPASS II 15x8
OS108FSR 15x8
OS 160 TWIN 15x10
* Supercharged version
ENGINE MOUNT
J-TECJT-120SP(SV)**
J-TECJT-ST125(SV)**
J-TECJT-122(SV)**
J-TECJT-M108(SV)**
Mount incl w/ engine
SPINNER
2-3/4"
3"
2-3/4"
2-3/4"
3"
** "SV" denotes the rubber-cushioned version of this mount, which is recommended.
The above components you select will determine how you build the fuselage, so it is important that
you have these components close at hand while building
MUFFLER SELECTION FOR SUPERTIGRE 2500
If you are using the Supertigre 2500 engine, you have two muffler choices One is the standard
SuperTigre "S 3000" silencer that is made for this engine, and which is outlined on the plans If you prefer a
more conventional style muffler, you may choose the J-TEC "JT-3000S" muffler which was custom made as
a result of this project (it is pictured in an Ultra-Sport 1000 on the cover of the April, 1992 issue of R/C
Modeler magazine) Both mufflers work well, but they are very different styles (See the photos on page 43)
LANDING GEAR CONFIGURATION
The Ultra-Sport 1000 may be built with a
"taildragger" or "tricycle" landing gear
configuration, and a retractable main gear may be
installed if you want to really "clean up' this airplane
for ultra-smooth and precise aerobatics.
The Ultra-Sport 1000 was not designed to
accommodate a nose gear retract, therefore if you
want retracts, you'll have to use the "taildragger"
configuration
You have a few choices regarding retracts,
and you should read the following before selecting
the retracts to be used in your plane.
experienced breakage in a couple of instances
involving moderately hard landings
2. The Robart company has indicated that the
following pneumatic retract system will work for
airplanes up to 12 lbs using stock wire struts,
but that the Robostruts should be used for
planes over 12 lbs Listed here are the Robart
items needed for the complete system #606
Retracts, #650 Robostruts, #188 Air control kit,
#190 Quick disconnects, #189 Airline
restricters, #164G Pump w/ gauge, #170 Air
line retainers
3. At the date of this writing, Robart has also
indicated that they will have new heavy-duty
mechanical retracts with 3/16" wire struts
available for this airplane These retracts,
although not tested in the US1000, may be
ideal for this airplane you may want to check
with your hobby dealer regarding the availability
of these retracts.
1. The retracts shown in this book are B&D 90-
degree 2-gear mains These units are
mechanical and are supplied with 5/32" wire
struts which are not considered strong enough
for this airplane, therefore, this kit includes
3/16" wire struts which you may install in the
B&D retract units by drilling them out Although
this system has worked reliably for us. we have
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