Rans S-21 OUTBOUND User manual

09/11/2018
S-21 OUTBOUND
ROTAX 915iS INSTALLATION
TEXT MANUAL
Serial Number:
Registration Number:
COPYRIGHT ©
RANS DESIGNS
4600 HWY 183 Alt
HAYS, KANSAS, USA 67601
785-625-6346
www.rans.com

09/11/2018
RANS S-21 OUTBOUND TEXT MANUAL 14-1
BEFORE BEGINNING ASSEMBLY
TAKE INVENTORY:
You must complete an inventory within 60 days
of receiving your kit.
We check and re-check and are 99.9% certain that if we say we shipped it, we did. The
first task in building your kit is to inventory the parts using the packing list provided. It is
your job to keep all parts organized and accounted for. We cannot provide missing parts
cost free after 60 days. Use the supplied pack list to verify that everything that we
packed is in the box. The fast way to inventory is to use the Priority Number that
appears on the Part Number labels, these will match the pack list in numeric order. Go
through the list item by item. If anything is not there that should be, please contact our
parts department immediately.

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RANS S-21 OUTBOUND TEXT MANUAL 14-2
ROTAX 915iS - ENGINE MOUNT INSTALLATION
(AFTER FIT-UP OF FIREWALL & BOOT COWL)
ASSEMBLY
1. Become familiar with the ROTAX 915iS PARTS MANUAL DRAWINGs and
collect the parts shown in the drawing.
2. Modify the firewall in accordance with FIGURES 11-01/915iS through FIGURES
11-01L/915iS
ROTAX 915iS – FIREWALL ITEMS INSTALLATION
1. Gather the applicable parts shown in the parts manual.
2. Modify the firewall to match FIGURES 11-01/915iS – 11-01L/915iS. Fit the firewall
to the fuselage before, and double check that the placement of the items will not
interfere with the welded cage structure.
3. Cut the spacer bushings from raw stock and attach the oil bottle mount to the
firewall. Then secure the oil bottle to the oil bottle mount using hose clamps.
NOTE: The orientation of the top of the oil bottle does matter, but can be
repositioned when installing the oil lines, adjust the clamp that holds the oil bottle
cap to the oil bottle, so it is easier to service at time intervals and condition
inspections.
4. Rivet the mount bracket for the coolant recovery bottle to the firewall and secure the
coolant recovery bottle to the bracket via hose clamp.
5. The firewall pass through holes can be made from the raw stock provided or
sourced through vendors such as aircraft spruce.
(AFTER INSTALLING ALL ACCESSORIES ON FIREWALL)
ENGINE MOUNT INSTALLATION
1. Become familiar with the ROTAX 915iS PARTS MANUAL DRAWINGS and collect
the parts shown in the drawing.
2. Install Engine Mount after making sure all accessories are located on firewall.
3. Ream the engine mount bushings of the engine mount and the bushings in the
cage on the firewall using a 5/16” ream.

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RANS S-21 OUTBOUND TEXT MANUAL 14-3
4. Bolt the engine mount to the firewall. Note the hardware orientation. NOTE: Before
torquing hardware, look ahead at the electrical parts page, some of the 4 AWG
ground wires attach to the upper right-hand bolt of the engine mount. NOTE: If
building a trike, place the trike nose gear mount behind the engine mount and leave
the two spacer washers out.
5. Torque the hardware to AN Standards.
6. Bolt the ROTAX Suspension Mount (supplied on your 915iS) to the RANS AFT
mount using the hardware, spacers and rubber isolators called out in the parts
manual. NOTE: The ROTAX Suspension Mount holes are 10.5mm, while the
hardware called out is 3/8”. This is as intended by ROTAX. Also note that they
have a supplied welded on nut down by the Turbo that will be used during the
installation.
7. Once the ROTAX Suspension Mount is properly torqued to the AFT Mount, safety
wire the lower right hand bolt head to the engine mount frame. This is the nut that
is welded to the turbo bracket, and the only nut that is not a self-locking nut.
ROTAX 915iS - ENGINE ELECTRICAL
(FINAL INSTALL OF ENGINE)
Due to the wide selection of switches, circuit breakers, connectors, gauges,
flight systems, etc., which may be used RANS builders, RANS does not
supply these items with the kit.
Electrical wiring can be aided with the use of Buss Bars for Master, Ground and Avionic
power.
(ECU INSTALLATION)
1. Refer to the parts catalog and select the required components for assembly.
2. Drill four holes in the firewall at the locations depicted on FIGURE 11-01/915iS &
11-01A/915iS.
3. Cut the four spacer bushings from raw stock.
4. Attach the Engine Control Unit to the firewall as shown in the parts diagram.
(SOLENOIDS INSTALLATION)
5. Refer to the parts catalog and select the required components for assembly.
6. Drill two holes in the firewall at the locations depicted on FIGURES 11-01/915iS
& 11-01B/915iS for the start solenoid. These holes will be upsized large enough
for the grommet to be inserted.

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RANS S-21 OUTBOUND TEXT MANUAL 14-4
7. Insert the grommet into the firewall. The isolator plate will go around the
grommets and isolate the starter solenoid from the firewall. Pin the Starter
solenoid to the firewall through the grommets.
8. Tighten the hardware to a snug fit, but do not overtighten. There should be very
little movement in the solenoid.
9. Drill two holes in the firewall at the locations depicted on FIGURES 11-01/915iS
& 11-01B/915iS for the master solenoid. Bolt the master solenoid to the firewall
and tighten the hardware.
(FUSEBOX INSTALLTION)
1. Refer to the parts catalog and select the required components for assembly.
2. Fabricate two pieces from baggage compartment angles to make two fuse box
mounting angles. Refer to FIGURE 11-02/915iS.
NOTE: These measurements are for reference only, please double
check them to your fuse box and engine mount.
3. Assemble the fuse box to the two mounting angles. Tighten all hardware.
4. Using the #30 hole called out in FIGURE 11-02/915iS, cleco the PCV Mount to
the angle, align the mount perpendicular to the fuse box mount angles. Transfer
drill the rest of the #30 holes. Debur the holes and cleco back in place.
5. Attach the mounting angles to the engine mount in the location provided in
FIGURE 11-02A/915iS. Tighten all hardware.
6. Position the PCV mount plate on the backside of the fuse box mount angles.
NOTE: Position in a way that avoids kinks in the tubing coming off the pressure
control valve. Install the PCV to the PCV mount. Rivet the mount plate to the
angles.
7. Install all supplied battery cables in accordance with the parts manual.
NOTES: Where the battery cables attach to the engine mount, it is
best practice to sand the powder coat down to bare metal for a
good ground. There should be no continuity between the
“AIRFRAME” ground and the “EMS” ground of the fuse box. Refer
to your ROTAX 915iS Installation manual for further details.
ROTAX 915iS – OPTIONAL BATTERY BOX ASSEMBLY &
INSTALLATION
(FINAL INSTALL OF ENGINE)
ASSEMBLY
1. Refer to the parts catalog and select the required components for assembly.
2. Firewall should have been drilled to match FIGURE 11-01C/915iS or 11-
01E/915iS, depending on which battery you have chosen.

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RANS S-21 OUTBOUND TEXT MANUAL 14-5
NOTE: Depending on the battery option used, these four holes through
the firewall will be different.
Power Sonic Battery Box
3. Cleco Support Angles to inside of Front Plate. Refer to the PARTS MANUAL
DRAWING. Transfer drill #30 and rivet. Base of Battery will set on Support
Angles.
4. Align one edge of Battery Box Front Plate with edge of Battery Box Mount Plate.
Clamp together and transfer drill #11 though upper and lower mount holes in
Mount Plate and cleco.
5. Slip Battery into assembly. Align free edge of Plates; pull Front Plate against
battery. Check to see if Battery can be slid in and out. If battery cannot be slid in
and out, then loosen fit slightly to allow easier removal. Clamp and transfer drill
#11 through upper and lower mount holes and cleco.
6. Transfer drill #30 the center holes in Mount Plate, and rivet from the AFT side.
7. Slide the Battery Bar through the holes in the Battery Box assembly. Modify the
Battery Bar per FIGURE 11-01D/915iS. Remove Battery from Battery Box
assembly
INSTALLATION
8. Bolt Battery Box assembly to firewall.
9. Install Battery and Battery Bar. Install Small Cotter Pins to retain Battery Bar.
10.Refer to the ENGINE ELECTRICAL section for Battery Cable and routing.
EarthX Battery Box
1. Rivet nut plates to retainer clips.
2. Cleco the Battery Box Front Plate to the Battery Box Mounting Plate and Rivet
using two rivets as depicted in the parts drawing.
3. Fabricate four spacer bushings with the appropriate raw stock.
4. Mount the battery box to the firewall with the hardware called out in the parts
manual.
5. If there is any play between the battery and the battery box, the foam supplied
with the EarthX battery is there for a shim to tighten the fit up.
ROTAX 915iS - FUEL SYSTEM
(AFTER INSTALLATION OF ENGINE)
1. Refer to the parts pages and select the required components for assembly.

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RANS S-21 OUTBOUND TEXT MANUAL 14-6
INSTALLATION OF FINE FUEL FILTER TO FIREWALL)
NOTE: Fuel Filter comes with the engine.
2. Install the two AN fittings into the filter. Make sure to use the supplied copper
crush washers.
3. Mount the Fuel filter to the firewall in the location depicted in FIGURE 11-
01F/915iS.
4. Install the two firewall bulkhead fittings in the lower left-hand portion of the
firewall. See FIGURE 11-01G/915iS.
5. Install the fuel lines as per the parts manual and torque to the appropriate AN
value.
INSTALLATION OF FUEL PUMP AND COARSE FILTER
6. Transfer drill the fuel pump tray to the fuel pump tray support using a #40 drill bit,
cleco as you go.
7. Upsize the holes to #30, debur and rivet the tray support to the fuel pump tray.
8. Using ¼” edge distance, transfer drill the fuel pump tray to the two welded tabs
on the fuselage. These two tabs also pickup the aft portion of the pitch servo
tray.
NOTE: If an autopilot is not being used, it will take an additional fuel
pump tray and fuel pump tray support. These two parts, if used,
will rotate 180 degrees from the original parts. See FIGURE 11-
03/915iS.
9. Transfer drill the fuel pump tray support(s) to the fuselage belly skin and cleco in
position.
10.Remove the fuel pumps from the stainless steel ROTAX box it is mounted in.
Snip the pinch clamp bands and flip the fuel pumps upside down and attach to
the ROTAX fuel pump saddle using the appropriate hose clamps.
NOTE: Write the serial number of your fuel pumps down. They will
be upside down and hard to see later for inspection and service
bulletins during condition inspections.
11.Install two fittings to the fuel valve using thread sealant. Refer to FIGURE 11-
03A/915iS and the parts manual.
12.Remove the handle from the fuel valve and install the valve to the two tabs of the
fuselage steel frame. Use the mount brackets as shown in FIGURE 11-
03A/915iS. Re-install the handle to the fuel valve.
NOTE: Valve should be "ON" when valve handle is AFT and "OFF"
when valve handle is UP.
13.Install the fuel line from the valve to the fuel pump outlet. This will help locate the
fuel pump location.

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RANS S-21 OUTBOUND TEXT MANUAL 14-7
14.Build up the coarse fuel filter using the parts called for in the parts manual. The
filter itself is marked as inlet/outlet. Write the orientation of the filter on the filter
shell for future reference. Tighten all the fittings.
15.Install the fuel filter to the fuel pump inlet. Also install the fuel line from the
header tank outlet to the fuel filter. This will also help locate the fuel pump on the
tray.
16.Find the optimum position of the fuel pump on the fuel pump tray and mark
where the studs rest. Remove the fuel pump and drill these four locations.
Remove the fuel pump tray and debur all parts. Reinstall the tray and rivet to the
belly skin and bolt to the welded tabs. Reinstall the fuel pumps using the
hardware called out in the parts manual.
17.Connect fuel lines from the fuel valve to the by-pass block to the outlet firewall
bulkhead fitting. From the return firewall bulkhead fitting to the by-pass block.
From the by-pass block to the fuel check valve (check orientation) and from the
fuel check valve to the return inlet of the header tank.
18.Connect fuel lines on the forward side of the firewall. From the outlet bulkhead
fitting to the fine fuel filter. From the fine fuel filter to the fuel inlet rail and from
the fuel outlet rail to the return bulkhead fitting at the firewall.
ROTAX 915iS – HEADER TANK ASSEMBLY
1. Locate Header Tank Mount per FIGURE 11-03B/915iS. Transfer drill #30
through each tab. Glue Rubber Edging to top edge of Mount flanges. Rivet
Header Tank Mount to top of tabs.
2. Locate and drill fitting holes in Header Tank per FIGURE 11-03C/915iS. Do NOT
drill the sump drain holes until fitting of the tank to the fuselage. For drilling
the holes, a 1/2" Unit-Bit®and 3/4" Unit-Bit® work best. Locate center of each
hole with a #30 drill bit, then drill full size. Deburr all holes. Thoroughly clean tank
several times by using a shop-vac and then rinsing with water. After confirming
that all foreign material has been removed, let dry prior to installing fittings.
NOTE: If it is anticipated that the plane will be converted between
Trike and Taildragger, then it is recommended to install sump
drains in both locations.
DOUBLE & TRIPLE CHECK HOLE LOCATIONS BEFORE DRILLING.

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RANS S-21 OUTBOUND TEXT MANUAL 14-8
3. To install the fuel fittings into the tank, obtain a piece of wire. Safety wire works
well. Insert wire through one of the fitting holes in the tank and up through the
filler neck. Refer to FIGURE 11-03D/915iS. Install an O-Ring onto the tank
withdrawal fitting and slide this assembly over the wire extending from the filler
neck. Bend a loop in the end of the wire to keep the fitting and O-Ring from
falling off. Pull the fitting through the hole. Slide a flat rubber washer, thick steel
washer, and a retaining nut over the wire and onto the fitting. Apply Loctite to
threads, install the nut on before removing the wire.
CAUTION: Do NOT get Loctite on the rubber washer.
4. Use an Allen wrench inserted into the tank fitting to hold the fitting while
tightening the retaining nut.
IMPORTANT: Do not allow the fitting or thick washer to rotate while
tightening or leaks may occur.
HINT: Prevent the thick washer from turning by holding with
needle-nose Vise-Grips.
5. Apply thread sealant to fittings and install into the tank fittings. Again, allow no
rotation of the tank fitting. Refer to the parts manual for the correct parts.
6. Perform a leak test by capping off all fittings and pressurizing the tank to 1 PSI
and let set for a period of time.
CAUTION: Damage may result from over-pressurization. While the
tank is pressurized, check for any leaks by spraying a soap/water
mixture onto the tank and around the fittings. To cap off the fittings
use a 1" segment of fuel line with a bolt inserted, and fuel line
clamps or similar. An alternate test is to fill the tank with water and
let it sit for approximately 48 hours.
7. Modify Header Tank Mount Channel per FIGURE 11-03E/915iS. Position Header
Tank flush with front of Mount. Use large hose clamps to secure tank to mount.
NOTE: Modified Mount Channel will position under hose clamps,
on top of tank, and be positioned so that Channel ends are flush
with sides of header tank.
LOCATING HEADER TANK SUMP VALVE HOLE THROUGH BELLY SKIN
8. Mark on the outside of the tank on each side next to the sump valve as per
FIGURE 11-03F/915iS. This allows location of the hole through belly skin with
the tank installed.
9. Set the header tank in place. Transfer the marks on the tank to the belly skin.
Remove the tank and project the marked lines at 90° to the sides of the tank until
they intersect.

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RANS S-21 OUTBOUND TEXT MANUAL 14-9
10.Drill a #40 in the skin at the intersection. Set the header tank securely in place.
Drill #30 through the hole in the skin and the header tank. Use a step drill or
several sizes of drill bits to work up to the required size hole for the sump drain
fitting.
(AFTER WINGS MOUNTED TO FUSELAGE)
11.After wings are mounted to fuselage in final assembly, route fuel withdrawal line
from each wing and the fuel vent line from the left hand wing, down behind
Station 3 and to the header tank. Secure as desired using plastic ties. Add a
clear plastic tape or split fuel hose as anti-chafe wherever the lines contact the
fuselage frame or other parts.
OPTIONAL LOW FUEL WARNING KIT
1. Become familiar with the Optional Low Fuel Warning Kit on the Header Tank
PARTS MANUAL DRAWINGS and collect the parts shown in the drawings.
2. A 5/8" hole will need drilled in the side of the Header Tank. If not, refer to
FIGURE 11-03C/915iS. Replace Silicon Washer provided with Low Fuel Warning
Switch with 5/8" Rubber Washer. Install Low Fuel Warning Switch into Header
Tank. Be sure to orientate the switch to allow electrical continuity (closed circuit)
when installed. Use a continuity tester (Ohmmeter) to be sure. Refer to FIGURE
11-03G/915iS. As the header tank fills with fuel, the switch will open, turning off
the LED Indicator Light.
3. Install 5/8" Rubber Washer, 5/8" Steel Washer and plastic nut on outside of tank
and tighten. Double check to be sure the switch is orientated correctly.
4. Locate LED Indicator Light in instrument panel. Connect to Low Fuel Warning
Switch per FIGURE 11-03G/915iS. Do not forget to include a proper sized
breaker or fuse.
NOTE: Alternatively, the low fuel switch can be wired directly to an
EFIS as a discrete. This will allow you to not need the LED and
can be user inputted as a LOW FUEL WARNING!
ROTAX 915iS - COOLING SYSTEM INSTALLATION
(AFTER INSTALLATION OF ENGINE)
ASSEMBLY
1. Refer to the parts catalog and select the required components for assembly.
2. Attach the two oil cooler mounts to the gear box. Note the two spacer washers,
they are not used for Airmaster Propeller Installations.