Evolution Engines 62GXI User Manual

62 GXI

Evolution® Gas Engines

NOTICE

All instructions, warranties and other collateral documents are subject to change at the sole
discretion of Horizon Hobby, LLC. For up-to-date product literature, visit horizonhobby.com
and click on the support tab for this product.

MEANING OF SPECIAL LANGUAGE

The following terms are used throughout the product literature to indicate various levels
of potential harm when operating this product:

NOTICE: Procedures, which if not properly followed, create a possibility of physical property
damage AND a little or no possibility of injury.

CAUTION: Procedures, which if not properly followed, create the probability of physical
property damage AND a possibility of serious injury.

WARNING: Procedures, which if not properly followed, create the probability of property
damage, collateral damage, serious injury or death OR create a high probability of
superficial injury.

WARNING: Read the ENTIRE instruction manual to become familiar with the features of
the product before operating. Failure to operate the product correctly can result in
damage to the product, personal property and cause serious injury.

This is a sophisticated hobby product and NOT a toy. It must be operated with caution and
common sense and requires some basic mechanical ability. Failure to operate this Product in a
safe and responsible manner could result in injury or damage to the product or other property.
This product is not intended for use by children without direct adult supervision. Do not use with
incompatible components or alter this product in any way outside of the instructions provided by
Horizon Hobby, LLC. This manual contains instructions for safety, operation and maintenance. It
is essential to read and follow all the instructions and warnings in the manual, prior to assembly,
setup or use, in order to operate correctly and avoid damage or serious injury.

CAUTION: This product can become extremely hot when in use, which could lead
to burns.

Age Recommendation: Not for children under 14 years. This is not a toy.

Safety Warnings

Model engines produce a substantial amount of power, which can create unsafe situations if not
used correctly. Always use common sense and observe all safety precautions when operating,
handling or performing any procedure involving your engine. Failure to follow safety precautions
could result in serious injury and property damage.

• Always ensure spectators, especially children, are at least 30 feet away when running
the engine.

• Always ensure that the propeller is securely attached to the engine shaft and all retaining
fasteners are tightened properly before EACH flight. Use of blue threadlock to tighten nuts
is advisable.

• Always keep small parts out of the reach of children as they can be choking hazards.

• Always secure the airplane before powering the engine.

• Always keep your face and body away from the path of the propeller blades when starting

or running your engine.

• Always stand behind the propeller when making carburetor adjustments.

• Always wear safety glasses or goggles when starting and running your engine.

• Always keep your fuel in a safe place away from sparks, heat or anything that can ignite.

• Always ensure the aircraft is secure and will not move once the engine is started.

• Always rebind your transmitter to your receiver(s) after setup and before first flight.

• Always ensure the throttle failsafe is set to low throttle in your transmitter.

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• Always perform a range check prior to flight.

• Always use the throttle linkage to shut off the air or turn off the engine power switch to stop

the engine.

• Never use hands, fingers, or any other body part to stop the propeller.

• Never throw any object into a propeller to stop it.

• Never run the engine in the vicinity of loose small objects, such as gravel or sand, to avoid

the propeller uncontrollably throwing such materials.

• Never wear loose clothing or a loose neckstrap when operating your model engine as these
items could become entangled in the propeller.

• Never have loose objects such as screwdrivers, pencils, etc. in your pockets when operating
your model engine. These could fall into the propeller.

• Never allow fuel to come into contact with eyes or mouth. Gasoline and other fuels used
in model engines are poisonous.

• Always ensure gasoline and fuel are stored in a clearly marked container away from
the reach of children.

Precautionary Guidelines

• Always mount the engine securely on a bench mount or high-quality engine mount.

• Always use the correct size and pitch of propeller for your engine. Refer to the Propeller Chart

in this manual.

• Always confirm proper balance of your propeller prior to installation of the engine. Failure
to do so could result in damage to the engine and/or airframe.

• Always utilize an electric starter to start your engine.

• Always discard any propeller that is nicked, scratched, cracked or damaged in any way.

• Always run your model engine in a well-ventilated area. Model engines can produce possibly

harmful carbon monoxide fumes.

• Always store your fuel safely in a sealed, water-resistant container.

• Always store fuel in a cool, dry location. Do not allow fuel containers to come in direct

contact with concrete, as the fuel may absorb moisture.

• Always responsibly discard fuel if there is condensation and/or water inside the fuel
container.

• Never return unused fuel from the fuel tank back into the fuel container.

• Never attempt to repair or modify a propeller beyond its intended use.

• Never handle model engines, mufflers and/or tuned pipes until they have had time to cool.

They can become extremely hot when in use.

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Introduction

Thank you for purchasing the exciting new Evolution® 62 GXI engine. A first in gasoline RC engines,
the 62 GXI features a throttle body fuel injection system. No longer will you have to deal with
needle valve settings and tuning your engine. The 62 GXI automatically manages fuel metering,
letting you worry about more important things like flying! Mounting the 62 GXI is simple with the
overall dimensions designed to fit current giant-scale offerings. Because its prop, muffler, and
mounting dimensions match other popular 50cc and 60cc engines, the 62 GXI is a drop-in fit for
many existing 50 –60cc airframes.

62cc GXI Gas Engine Design

Building upon our proven small block gas engines, the 62 GXI takes ease of use and reliability to
the next level.

Step 1 Start with a ‘clean sheet of paper’. This is a completely new engine designed as a

powerhouse with user-friendly qualities for 50–60cc airplanes. Making the engine
powerful, reliable and easy to operate were key design considerations.

Step 2 Design a new throttle body fuel injector system around this engine. Fuel injectors have

never been used on gasoline RC engines, although they have become standard for other
industries like the automobile industry. Bringing this technology to RC engines enables
flyers to enjoy more flying time with less hassle.

Step 3 Include an effective, wraparound style in-cowl muffler with the engine so flyers won’t

have to source a muffler before they can fly.

Step 4 Design operating accessories that enhance the gasoline engine experience.

• The construction and reliability of the fuel delivery system to the fuel injector is
critical. Microscopic pieces of dirt will wreak havoc on the injection system. The
included Sintered Plastic Filter Clunk (EVOA121) takes care of the dirt problem.
It is mandatory to use the included filter to ensure trouble-free operation.

• The same holds true for air bubbles from the tank or any small leak in the
fuel tubing; even small bubbles are simply not tolerated in this system. The
included filter and tubing ensure no air bubbles affect the system.

• We found that popular gasoline fuel tubing has its weak points. Normal

®

Tygon

tubing (the go-to choice for gasoline engines) does not withstand high
temperatures well and tends to get stiff and brittle with use, and Neoprene
tubing tends to swell with exposure to gasoline. Swelling will eventually lead
to the fuel line slipping off if the line is not secured with a wire tie or similar.
Viton® tubing withstands not only the high temperatures, but its durability is
much greater than that of either Tygon or Neoprene. The added bonus is that
it fits and holds well to the fuel fittings without any need for additional wire
or tie-wrap keepers. We recommend you purchase Viton tubing for optimal
performance.

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Included Content

Engine

EVOM6 Wraparound Inverted In-Cowl Muffler
EVOG620328 Exhaust Mount Bolts with Gasket M5 x 16
EVOG33350 Spark Plug (CM6)
EVOA107 Evolution/Spektrum™ Telemetry RPM Adapter Cable
EVOA121 Sintered Plastic Filter Clunk

Optional Items

EVOA100 Optical Electronic Ignition Kill Switch
EVOA108 Locking Fuel Can Cap
EVOX1001Q Evolution Synthetic 2-Cycle Oil
HAN155 Ultra Fuel Pump
HAN156 Tachometer

A

B

C

D

E

F

A. Prime Port
B. Idle Screw Adjustment
C. Fuel Feed (F)
D. Testing Port (T), Capped
E. Fuel Return (R)
F. Throttle Arm

Installing the Engine

Secure the engine to the airplane firewall using either M6 or 1/4–20 bolts. Use spacers or
standoffs as needed to set the correct firewall-propeller distance according to the airplane
manufacturer’s instructions.

Refer to end of the manual for a full-size firewall template cutout.

WARNING: Tighten all engine mounting screws before each flight. If you do not tighten
the engine mounting screws, the screws may vibrate loose and cause the engine to
separate from the fuselage.

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Installing the Muffler

The muffler mounting accessory package
includes mounting screws (2), lock washers
(2), muffler gaskets (2) and an L-wrench.

We suggest using high-temperature RTV as a
locking agent on the muffler screws to keep
them tight.

Connecting the Throttle Linkage

1. Put a lock washer on each of the muffler
screws. Push the muffler screws through the
muffler.

2. Place the muffler gasket over the muffler
mounting screws.

3. Align the muffler gasket with the exhaust
opening and the muffler mounting screws.

4. Tighten the muffler screws.

6. Move the linkage connected to the throttle
body to full-idle (forward). On the servo
arm, find the hole that is closest to 16mm
(5/8 in) from the center of the arm. Mark the
pushrod where it meets this hole.

1. Use a 3mm ball-link to attach the throttle
linkage to the throttle arm on the throttle
body.

2. Power ON the transmitter and receiver. Move
the throttle stick and throttle trim to center.

3. Place the servo arm on the throttle servo so
the arm is perpendicular (90°) to the throttle
linkage.

4. Ensure the throttle servo is moving in the
appropriate direction. The throttle servo arm
should move towards the engine when the
throttle stick is moved to low throttle. If it
doesn’t, reverse the servo direction in your
transmitter. If you use servo reversing, you
will need to rebind your transmitter to the
receiver for failsafe to function properly.

5. Move the throttle stick to low throttle on the
transmitter. Reduce the throttle trim to its
lowest setting.

16mm

7. Using pliers, bend the pushrod so there is a
90° bend at the mark.

8. Using a pushrod keeper, secure the pushrod
in the servo arm.

9. Check that the throttle arm on the throttle
body can travel fully open and fully closed
(both have hard stops). Adjust your
transmitter endpoints to ensure full travel.

10. If there is a large difference between the

endpoints, adjust the endpoints and sub­trim to find a balance where the endpoints
are approximately within 10% of each
other.

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Throttle Curve Setup

The engine’s throttle body flapper valve provides
non-linear engine response to throttle changes
(greater power increase between low throttle to
50% than 50% to full throttle). We recommend
using the Throttle Curve feature on your
transmitter to provide a more linear response.

Using these Throttle Curve settings, shown
from a Spektrum™ DX18 transmitter screen
shot, with a properly setup throttle linkage will
provide a very linear feel to the throttle.

Attaching the Fuel Lines

Fuel Feed (F)

Fuel Return (R)

Refer to the Fuel Delivery System section for
information on plumbing the fuel tank. This
system uses a new setup and requires special
attention when setting up the fuel tank.

1. Connect the medium diameter Viton fuel

tubing to the fuel tank supply line and the
fuel tubing connector on the throttle body
labeled “F”.

2. Connect the medium diameter Viton fuel

tubing to the vent line. Run this fuel line
either around the back of the tank or make
a loop on top of the tank to create an “anti­syphoning” loop. Take the other end of the
fuel line and route it outside the airplane
fuselage.

1. Ensure you have set up the throttle linkage
as described in the Connecting the Throttle
Linkage section. It is very important that the
low throttle and high throttle endpoint travel
of your servo be as close to even as possible
(i.e. Low throttle, trim closed -100%, high
throttle 100%). A variation of as much as
10% between these two values is tolerable.

2. Enter the numbers from the diagram into
your transmitter’s Throttle Curve menu and
activate exponential (if applicable).

3. Once the engine is started and running
correctly, check the feel of the throttle
response. Adjust it to your liking through
your transmitter’s programming screen.

3. Connect the medium diameter Viton fuel
tubing to the return port on the throttle body
labeled “R”. Connect the other end of this
line to a tee. Connect one end of the tee to
the fueling line in the tank and the other
end to the aircraft fuel inlet wherever you
feel is most appropriate. We recommend
you use an external fuel dot in order to fuel
the airplane without needing to remove any
hatches or cowls.

C

B

A. Tank Vent Tube
B. Fuel to EFI Unit
C. Return Line from EFI and Tank Fill Tube

A

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