INTRODUCTION

BECOMING FAMILIAR WITH YOUR ENGINE

If you are familiar with the operation of model engines or just canít wait to

run your new engine, please read through the Quick-Start Guide included.

This guide will help you get started right away and also includes some good

recommendations. We do recommend reading through these Operating

Instructions in their entirety to familiarize yourself with the features and

operation of your new engine. We have also included a Troubleshooting

Guide should you encounter any problems.

Please use the photos below to familiarize yourself with the components of

your new Magnum XL RFS series engine.

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CAUTION - PLEASE READ!!

Global Services 18480 Bandilier Circle Fountain Valley, CA 92708 Phone: (714) 963-0329 Fax: (714) 964-6236 Email: service@globalhobby.com

Both Engines Feature:

● Ringed-Piston Design for Long Life and High Power

● Rear-Updraft, Dual-Needle Carburetor w/Choke

● High-Flow Quiet Muffler

● Dual Ball Bearing-Supported Crankshaft & Camshaft

● Dual Bushing-Supported Connecting Rod

Thank you for choosing a Magnum XL RFS series aircraft engine. The XL .80RFS

and .91RFS engines are single cylinder, four-stroke engines incorporating

an aluminum piston, iron ring and steel sleeve for long life and high power

output. A dual needle valve carburetor for precise fuel/airflow metering is

standard. Both engines feature a ball bearing-supported crankshaft and

camshaft, dual bushing-supported connecting rod, and a high-flow muffler

for more power and reduced noise. Your Magnum XL RFS series engine

was designed by expert engineers and built by master craftsmen using only the

highest quality materials and CNC machinery. These qualities provide the long

life and dependability you have come to expect from an engine of this caliber.

Magnum XL RFS series model airplane engines will consistently give you

dependable performance and reliability and will be a source of satisfaction

and pleasure if you follow these instructions as to the engineís proper and

safe use. You alone are responsible for the safe operation of your engine,

so act sensibly and with care at all times. This Magnum XL RFS series

model airplane engine is not a toy. It is a precision-built machine whose

power is capable of causing serious injury to yourself and others if abused or

misused, or if you fail to observe proper safety precautions while using it.

● Keep spectators, especially small children, at least 20 feet away from the

engine while it is running.

● Mount the engine securely in the airplane or on a suitable engine test

stand to run the engine. Follow the mounting instructions in your kit's

instruction manual or on the plans for individual mounting recommendations.

Do not clamp the engine in a vise to test-run it.

● Use the recommended size propeller and follow the proper procedure for

mounting the propeller. Use the correct size wrench to tighten the propeller

nut and the safety nut. Do not use pliers.

● Inspect the spinner, propeller, and propeller and safety nuts on a regular

basis, looking for any signs of nicks, cracks or loosening.

● To stop the engine, adjust the throttle linkage to completely close the throttle

barrel and therefore cut off the fuel/air supply. You can also pinch the fuel

line to stop the engine, but only if it is accessible. Do not throw anything into

the spinning propeller or attempt to use your hands to stop the engine.

● While the engine is running, stand behind the engine to make any

adjustments to the needle valves. Do not reach over or around the propeller.

Do not lean toward the engine. Do not wear loose clothing or allow anything

to be drawn into the spinning propeller while the engine is running.

● If you need to carry your model while the engine is running, be conscious

of the spinning propeller. Keep the airplane pointed away from you and

others at all times.

● Do not use tight-fitting cowls over the engine. They can restrict air from

flowing over the engine, which could result in engine damage from overheating.

ENGINE INSTALLATION

Engine Orientation

Your XL RFS series engine can be orientated in any position on the firewall.

Keep in mind that when the engine is mounted inverted, carburetor

adjustments will need to be made differently and the fuel tank may need to

be lowered. (See fuel tank size and orientation to carburetor on the next page.)

OPERATING

INSTRUCTIONS

Displacement: ................ .80ci (12.8cc) / .91ci (14.95cc)

Bore: ............................... 26.5mm / 27.7mm

Stroke: ............................ 24.8mm / 24.8mm

Practical RPM: ............... 2,000 - 12,000 / 2,000 - 12,000

Weight: ............................ 20.0oz / 20.7oz (w/o Muffler)

21.7oz / 22.4oz (w/ Muffler)

XL .80RFS/.91RFS ENGINE SPECIFICATIONS

For XL .80RFS and XL .91RFS

Series Four-Stroke Engines
The engine should be mounted to either a heavy-duty, glass-filled nylon

engine mount, a machined aluminum engine mount or an integrated hardwood

beam mount. Use only high-quality steel cap screws and related hardware

to mount the engine to the engine mount. The firewall in the airplane should

be aircraft grade 5-ply plywood no less than 5/16" thick and the firewall should

be reinforced to meet the torque and weight of the engine.

For More Information, Please Visit Our Website at http://globalservices.globalhobby.com

The muffler threads onto the exhaust pipe, which then threads into the engine's

cylinder head. First thread one cinch nut onto each end of the exhaust pipe,

then thread the muffler onto one

end. The muffler should be

threaded on at least 1/4î to

prevent vibration from damaging

the threads. Once you have

threaded the muffler onto the

exhaust pipe use an open end

wrench to firmly tighten the cinch

nut up against the muffler. The

exhaust pipe is adjustable to

better suit the installation of your particular application. Thread the exhaust

pipe into the engineís cylinder head. The exhaust pipe should be threaded

in no less than 1/4î to prevent vibration from damaging the threads. Once

you have threaded the exhaust pipe into place and into the proper position

for your application, use an open end wrench to firmly tighten the cinch nut

against the cylinder head.

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Ideally, the stopper in the fuel tank should be even with the high speed needle

valve or just slightly below it. Some models will only allow the fuel tank to be

mounted higher than the ideal location. A fuel tank that is positioned higher

than the ideal location usually doesnít pose any problem except when it is

mounted excessively higher and/or is used in conjunction with an inverted

mounted engine or during extreme aerobatic flight. If you mount the engine

inverted, we strongly suggest lowering the fuel tank so the stopper assembly

is slightly below the high speed needle valve. Doing this will prevent fuel

from siphoning into the engine and flooding it when the fuel tank is full. If

you cannot lower the fuel tank far enough, we suggest lowering it as far as

can be allowed in your particular application.

The size of the fuel tank used should be 12oz. - 14oz., depending on the

model and the length of flights desired. Use of a 14oz. tank will provide

between 10 - 15 minutes of run time at full throttle. Use of a fuel tank any

larger than 14oz. can lead to excessive leaning of the engine during flight

and is not recommended.

In some cases you may want the throttle arm on the opposite side of the

engine from how it comes

preinstalled. You can remove the

carburetor and reinstall it in the

opposite direction with no effect on

performance. To remove the

carburetor, loosen the two screws

holding the intake manifold in

place. Next, remove the two

screws holding the choke assembly/

carburetor to the engine. Remove

the carburetor by gently pulling it down off the intake pipe. To reinstall the

carburetor, apply machine oil to the o-ring inside the carburetor mounting

base and reverse the process, making sure to tighten all the bolts securely.

Engine Bolts & Firewall Requirements

Muffler Installation

Fuel Tank Size & Orientation to Carburetor

Carburetor Orientation

Choke Valve

Your XL RFS series engine is equipped with a choke valve to aid in priming

the engine for hand-starting. The

engine is choked by opening the

carburetor barrel completely and

turning the choke lever to close off

the carburetor opening. Fuel can

then be drawn into the engine by

turning the propeller. If the choke

lever is too short for your

particular application, fabricate a

longer choke lever out of 2mm

diameter piano wire and secure it into the choke assembly using the 1.5mm

grub screw. If the choke lever is more than 3" long we recommend supporting

the outer end of it to prevent excessive vibration.

Idle Stop Screw & Rotor Bolt

The idle stop screw adjusts the closure of the throttle barrel. Turning the idle

stop screw clockwise will make

the throttle barrel stay open more.

Turning it counter-clockwise will

allow the throttle barrel to be

closed more. Adjust the idle stop

screw so that you can close the

throttle barrel completely to shut

off the engine. The rotor bolt holds

the throttle barrel in the carburetor

body and prevents the throttle

barrel from being over-rotated in either direction. It does not require adjustment.

Periodically check the rotor bolt to ensure that it is tight.

Optional Needle Valve Extension

If an extension is required to adjust the high speed needle valve, use a 1.5mm

diameter wire of the necessary length. Loosen the grub screw in the side of

the needle valve, insert the wire into the end of the needle valve and tighten

the set screw firmly. If the extension is more than 3" long we recommend

supporting the outer end of the extension to prevent excessive vibration.

Propeller Installation

Your engine comes equipped with a main propeller nut and one safety nut.

For your safety, we recommend using both the propeller nut and the safety

nut to secure the propeller into place.

WARNING Before installing the propeller it must be properly balanced.

Running your engine using an out-of-balance propeller can lead to

excessive vibration, which will result in excessive stress and wear on both

the engine and the airframe. Balance the propeller using the method

recommended by the propeller manufacturer. Several products are

available to properly balance propellers. Ask your local retailer for more

information about these items.

Crankcase Breather Nipple

A nipple is located on the bottom of the crankcase. This is a breather nipple

and should not be plugged or have any part of the fuel system hooked to it.

Ideally, the nipple should be left as-is; however, a short piece of fuel tubing

can be attached to it and run outside of the cowling or fuselage.

WARNING Do not plug the breather nipple or the engine will not run

properly. If you place an extension on the breather nipple it should not be

more than 3" long.

Continued at Top of Next Page
Global Services 18480 Bandilier Circle Fountain Valley, CA 92708 Phone: (714) 963-0329 Fax: (714) 964-6236 Email: service@globalhobby.com

PROPELLER, GLOW PLUG & FUEL

The diameter and pitch of the propeller needed for your XL RFS series

engine will vary greatly depending on the application the engine is used in.

The weight, drag and the type of model and how you intend to fly it are all

factors in determining the correct size propeller to use. Experimentation

will be necessary to find the optimal size propeller for your particular

application. Ideally you want a propeller that the engine will turn in the

10,000 - 12,000 rpm range on the ground, yet power the airplane sufficiently.

Using a propeller that is too small will cause the engine to run at too high an

rpm. Using a propeller that is too large will cause the engine to run at too low

an rpm and cause it to lug down too much. In both instances this can lead to

premature engine wear and eventual failure.

PROPELLER SIZE RECOMMENDATIONS FOR XL .80RFS

Propeller Recommendation

Use for

Break-In

Glow Plug Recommendation

Glow plugs can make a big difference in the performance of your engine.

We recommend using a hot heat-range glow plug intended specifically for

four-stroke engines. Do not use a cold heat-range plug or a plug designed

for two-stroke engines. This can lead to erratic engine runs and eventual

engine wear and failure.

Fuel Recommendation

Fuel can make a big difference in the way your engine performs. We

recommend using two types of fuel with your XL RFS series engine. For the

break-in period you must use a fuel containing no more than 10% nitro

methane and no less than 18% Castor/synthetic blend lubricant. Use of fuel

containing more than the recommended percentage of nitro methane or only

synthetic lubricants will cause the engine to run too hot and result in excessive

wear and engine failure in a very short period of time. Once the engine has been

HIGH & LOW SPEED NEEDLE VALVES

High Speed Needle Valve

The high speed needle valve is used to meter the air/fuel mixture at full

throttle. Turn the needle clockwise to lean the mixture or turn the needle

counterclockwise to richen the mixture. When you start the engine for the

very first time the needle valve should be turned in completely, then backed

out 2-1/2 turns. When you start the engine after that, leave the needle valve

in the same position it was in when you shut down the engine.

Low Speed Needle Valve

The low speed needle valve regulates the air/fuel mixture at idle and during

transition from idle to full throttle. Turn the idle mixture screw clockwise to

lean the mixture. Turn it counterclockwise to richen the mixture. The idle

mixture screw is preset from the factory, but minor adjustments may need to

be made after the engine is broken in. To reset the mixture screw to the

factory setting, open the carburetor barrel completely. While holding

the barrel open, turn the mixture screw OUT until it stops. From this

point, turn the mixture screw IN 4-1/4 turns. This is the factory setting.

STARTING PROCEDURE

Your XL RFS series engine can be started using an electric starter or it can

be started by hand. For safety and ease of starting, especially when the

engine is new, we recommend using an electric starter. The following two

procedures should be done with the power to the glow plug off.

Starting Using an Electric Starter

When using an electric starter it is not necessary to choke and prime the

engine. The starter turns the engine over fast enough that the engine draws

fuel on its own. Priming the engine prior to using an electric starter can

cause the engine to "hydro-lock" or flood. This is a result of too much fuel in

the engine before it actually fires. Turning the engine over with an

electric starter while the engine is flooded can cause extreme damage

to the engine and/or cause the propeller assembly to come loose. Turn

the propeller through the compression stroke one time by hand to check

for a hydro-locked state before applying the starter.

13 x 6

12 x 6

12 x 8-10

13 x 7

13 x 8

The diameter of the crankshaft is 5/16". Using a 5/16" drill bit or a prop

reamer, enlarge the hole in the

propeller hub to fit the crankshaft.

Slide the propeller onto the

crankshaft, up against the thrust

washer. Slide the propeller

washer up against the propeller

and thread the prop nut into place.

Tighten the prop nut firmly to

secure the propeller in place, then

install and tighten the safety nut

against the propeller nut. When tightening the nuts, use an adjustable

wrench. Do not use pliers.

WARNING If you are installing a spinner onto your engine, the cone of

the spinner must not rub against the propeller. Allowing the spinner cone

to rub against the propeller could lead to propeller damage and eventual

propeller failure.

PROPELLER SIZE RECOMMENDATIONS FOR XL .91RFS

Use for

Break-In 14 x 6

13 x 6

13 x 8

14 x 8

adequately broken in (about 1/2 gallon of the recommended break-in fuel),

a fuel containing up to, but no more than, 15% nitro methane and no less

than 16% Castor/synthetic blend lubricant fuel can be used.

WARNING We do not recommend using fuels that contain only

synthetic lubricants. Synthetic lubricants have a much lower flash point

than Castor Oil lubricants. Flash point is the point at which the lubricant

begins to actually burn and lose its lubricating qualities. Using fuels

containing a blend of Castor Oil and synthetic lubricants results in an

engine that runs cooler and lasts longer. One lean run using a fuel

containing only synthetic lubricants can cause engine failure. Using fuels

with a Castor Oil and synthetic blend of lubricants greatly reduces this chance.

Starting by Hand

When starting the engine by hand always use a chicken stick or a heavy

leather glove. Never just use your bare hand or serious injury could result.

To make the engine easier to start by hand it should first be primed. This is

done by opening the carburetor barrel completely and turning the choke lever

to close off the carburetor opening. Fuel can then be drawn into the engine

by "pulling" the propeller through the compression stroke 2 - 3 times. This

will draw fuel into the engine. Release the choke lever and pull the propeller

through the compression stroke once to check for a hydro-locked condition.

3
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Setting the Low Speed Needle Valve

❑ 1) Start the engine and lean out the high speed needle valve as per the

previous steps. Close the throttle until the slowest reliable idle is reached.

Allow the engine to idle for about 30 seconds.

❑ 2) Quickly advance the throttle to full. If the engine just stops running as

soon as the throttle is advanced, the idle mixture is too lean. With the

engine stopped, richen the idle mixture about 1/8 of a turn.

❑ 3) Repeat steps # 1 and # 2 until the engine will transition from idle to full

throttle smoothly. Minor hesitation in the transition is normal.

❑ 4) If you quickly advance the throttle from idle to full and the engine seems

to be very rich during transition (i.e., lots of smoke coming from the exhaust),

the mixture is too rich. With the engine stopped, lean the idle mixture about

1/8 of a turn.

❑ 5) Repeat steps # 1 and # 4 until the engine will transition from idle to full

throttle smoothly. Minor hesitation in the transition is normal.

BREAK-IN PROCEDURE

IMPORTANT Your XL RFS series engine is a ringed engine. A ringed

engine is designed differently from a typical ABC designed engine that

you might be more familiar with; therefore you will not feel much hesitation

as the piston moves through the top of the stroke. A ringed engine does

not have any taper in the sleeve. Ring tension is what seals the

combustion chamber. When the engine is brand new, it will not feel like it

has much compression. This is because the ring has not yet been seated

with the sleeve. After the engine has been broken-in, compression will

increase. The break-in procedure will guide you through the steps

necessary to properly break in your new XL RFS series ringed engine.

Please follow the steps closely.

The break-in process allows the engine parts to perfectly fit each other and

properly protect each part from premature wear. The engine should be

broken in using a fuel that contains no more than 10% nitro methane and no

less than 18% Castor/synthetic blend ubricant. Fuel containing only

synthetic lubricants should not be used during the break-in procedure. For the

break-in procedure we recommend mounting the engine into the airplane it

will be used in. This way the muffler, fuel tank and throttle linkage can all be

tested in combination with the engine. If your airplane uses a cowling, it

should be removed during the break-in procedure.

❑ 1) Turn the high speed needle valve out 2-1/2 turns from the fully

closed position.

❑ 2) If you are using an electric starter to start the engine, follow the

procedure in the previous section. If you are starting the engine by hand,

follow that procedure in the previous section.

❑ 3) Open the throttle barrel to approximately 1/4 throttle. Connect the

power to the glow plug. Start the engine using an electric starter or by hand.

If starting by hand you will need to vigorously flip the propeller through the

compression stroke several times before the engine will start.

❑ 4) Once the engine starts, open the throttle barrel to about 1/2 throttle.

You may need to lean the high speed needle valve in about 1/4 turn to keep

the engine running at half throttle.

❑ 5) After the engine has been running about 1 minute, remove the power

from the glow plug and slowly advance the throttle barrel to full throttle.

Adjust the high speed needle valve so that the engine is running very rich.

You should notice excessive white smoke coming from the exhaust. Let the

engine run for approximately 10 minutes then stop the engine.

❑ 6) Let the engine cool for approximately 10 minutes then restart it. Set

the high speed needle valve mixture to a slightly leaner setting, about 1/4

turn more in. Let the engine run for about 5 minutes at this setting, then stop

the engine and let it cool for approximately 10 minutes.

❑ 7) Repeat the procedure in step # 6, while leaning the needle valve slightly

more each time. In all, you should run the engine about a total of 45 minutes

of actual running time. After 45 minutes of run time the engine is ready for

flight. Fly the airplane with the engine set as rich as possible, but with

adequate power to fly the airplane. After each flight, lean the mixture slightly.

Continue to do this for about 5 flights. At this point the engine should hold a

good setting on the high speed needle valve and you can begin to fine tune

the needle valve settings to increase performance.

OPTIMIZING THE MIXTURE SETTINGS

Now that your engine is broken in, you can set the high and low speed needle

valves for optimum performance.

WARNING Be careful never to lean the engine out too much. Remember

that the lubricants for your engine are suspended in the fuel. If you lean

out the fuel mixture too much you will also be lowering the amount of

lubricant entering your engine. Less lubricant means more chance of

your engine overheating and possible engine failure.

Continued at Top of Next Column

Setting the High Speed Needle Valve

❑ 1) Start the engine and remove the power from the glow plug. Allow

the engine to warm up for about 1 minute.

❑ 2) After the engine has warmed up, slowly lean the high speed mixture

until the engine reaches peak rpm. After reaching peak rpm, richen the

mixture slightly until an audible drop in rpm is heard. If you are using a

tachometer this should be between a 200 - 300 rpm drop.

❑ 3) With the engine running at full power, carefully lift the nose of the

airplane about 45o into the air. The mixture should not become too lean, but

you may hear a slight increase in rpm. If the engine sags, or loses rpm when

you hold the nose up, the mixture is too lean. If this is the case, slightly

richen the mixture and follow the test once more.

IMPORTANT Rpm will increase about 10% - 30% in the air. This is due

to the forward motion of the aircraft as it is flying. Because of this more air

is entering the carburetor, at a higher force, which causes the mixture to

lean out. Additionally, as the fuel level in the fuel tank goes down, fuel

draw becomes more difficult for the engine, especially during aerobatics,

thus causing the mixture to go lean. It is imperative that you set the

mixture rich while on the ground to compensate for the leaning

tendencies that will happen in the air. Always watch the exhaust during

your flight. The engine should leave a noticeable white smoke trail at all

times. If there is no smoke trail, the engine is running too lean. You

should land immediately and reset the mixture.

Information about engine maintenance, including

adjusting the valves and returning your engine for

warranty service can be found on the separate

sheets packaged with these Operating Instructions.

Magnum XL RFS series engines are distributed

exclusively by Global Hobby Distributors 18480 Bandilier

Circle, Fountain Valley, CA 92708

All contents copyright © 2003, Global Hobby

Distributors Version V3.0 May 2003
The following items are recommended for use with your XL RFS series

engine. These items are recommended for initial start-up and running.

Please read through the Operating Instructions for further details.

Fuel: We suggest Power Master 10% 2-Stroke Blend (P/N 275180) for

break-in.

We suggest Power Master 15% 4-Stroke Blend (P/N 275200) for

normal use.

We suggest using Power Master brand fuels. Power Master fuel comes in

10% and 15% nitromethane contents that can be used in your XL RFS

series engine. Power Master fuels are blended using only high-quality

nitromethane, methanol, Castor Oil and synthetic lubricants to provide

high power output, along with easy starting and unmatched lubricating

and heat dissipation qualities. For the extra lubrication necessary for

break-in, use 10% 2-stroke blend. After break-in, for extra performance,

use 15% 4-stroke blend.

Fuel Tank: Dubro 14oz. Fuel Tank (P/N 568543)

Dubro fuel tanks are a perfect match for your XL RFS series engine. This

size recommendation will give you about 10-15 minutes of run-time at full

throttle, and they are possibly the easiest fuel tanks to assemble and maintain.

Glow Plug: Thunderbolt Four-Stroke Glow Plug (P/N 115490)

The Thunderbolt Four-Stroke glow plug is designed to be used in four-stroke

engines using fuels containing 10% - 15% nitro content and in any

environment. It is a "hot" type of glow plug for easy starting, excellent

transition and incredible top end. The glow plug is also very durable and

able to withstand repeated use, day after day.

Propeller: APC 13 x 6 Propeller (P/N 609288) for XL .80RFS

APC 14 x 6 Propeller (P/N 609560) for XL .91RFS

We have found that XL RFS series engines run best using APC brand

props. They are designed to be very efficient and run quiet at high rpmís,

and they are also durable. Use this size prop to break in your engine,

then change to the prop that best suits your application. Use the guide in

the Operating Instructions to help you find the right size propeller.

Glow Driver: Magnum Glow Starter w/Meter (P/N 237438)

The Magnum glow starter is an excellent choice for heating the glow plug.

It uses a Sub-C NiCD, includes a meter to determine the quality of your

glow plug, and it also includes a charger to recharge the battery. Itís a

very economical product to purchase and can be used with any engine

that uses a glow plug.

Engine Mount: Magnum Adjustable Engine Mount (P/N 279950)

The Magnum adjustable engine mount is an aluminum beam mount that

mounts to a plywood firewall in the model. It is easy to install and is

adjustable to fit different sized engines, and it comes complete with

mounting hardware.

Engine Preparation

OUR RECOMMENDATIONS

QUICK-STARTING PROCEDURES

❑ 1) Mount the engine to the recommended engine mount. A strong

wood beam mount built into the airframe would also be sufficient.

❑ 2) Install the muffler and exhaust pipe onto the engine using the cinch

nuts provided. The exhaust pipe can be rotated to better suit the

installation in your model. Be sure to tighten the cinch nuts securely to

prevent the muffler and exhaust pipe from loosening.

❑ 3) Install the propeller to the engine using the propeller washer,

propeller nut and the safety nut provided. Tighten the nuts securely using

an adjustable wrench.

❑ 4) Connect the fuel lines to the carburetor and to the muffler. Do not

connect any fuel line to the breather nipple on the bottom of the crankcase.

❑ 1) Carefully turn the high speed needle valve in completely until it stops,

then turn the needle valve out 2-1/2 turns. This is the mixture setting for

initial starting. Do not adjust the low speed needle valve.

❑ 2) If hand starting, prime the engine by opening the throttle barrel

completely, closing the choke valve and flipping the prop through

compression 2 -3 times. If you will be using an electric starter, do not

prime the engine. The starter will turn the engine over fast enough to

draw fuel on its own.

❑ 3) Connect the glow starter to the glow plug. Open the carburetor

barrel to about 1/4 throttle and start the engine. If you are starting the

engine by hand, you will need to vigorously flip the prop several times

before the engine will start. Once the engine begins running, immediately

turn the high speed needle valve in about a 1/4 turn to keep the engine

running.

❑ 4) Advance the throttle to full while turning the high speed needle valve

in to keep the engine running. The engine should be producing a very

noticeable white exhaust from the muffler and sound like it is running rough.

Allow the engine to run for only about 5 minutes, then shut the engine off.

❑ 5) Now that you have started your engine, it must be properly broken

in. Proper break-in will seat all of the moving parts, particularly the piston

ring, sleeve and valve assemblies. This procedure takes about 45

minutes of run-time and is highly recommended. An engine that is properly

broken in will produce more power, be more user-friendly and last much

longer than an engine that does not receive a break-in period. For this

reason we highly recommend following the break-in procedure detailed

in the Operating Instructions before you run the engine further.

Engine Starting

XL .80RFS & XL .91RFS SERIES

AIRCRAFT ENGINE QUICK-START

AND TROUBLESHOOTING GUIDE

The following information is provided to get your new Magnum XL RFS

series engine running right away with minimal effort. We have listed

our recommendations for fuel, propeller, starting procedures and

other recommended accessories. Also included is general information

about the accessories needed for the engine that we hope you will

find helpful.

This Quick-Start Guide should not be used as a replacement for the

Operating Instructions included; rather, it should be used along with

the Operating Instructions. We highly recommend reading through

the Operating Instructions to familiarize yourself with each part of the

engine, along with the proper procedures for engine break-in and tuning.
1) Engine does not start A) Failed glow plug A) Replace glow plug with new one

B) Glow starter not charged and/or faulty B) Fully charge glow starter and/or replace

C) Engine not being turned over fast enough C) Use an electric starter to start engine

D) Low speed needle valve set too lean D) Reset low speed needle valve to factory setting

E) Old or contaminated fuel E) Replace with new fuel

F) Engine flooded with too much fuel F) Remove glow plug and expel fuel from cylinder

G) Faulty fuel tank and/or stopper assembly G) Check and/or replace fuel tank assembly

H) Air leak in fuel system and/or engine H) Replace fuel lines and/or tighten all engine bolts

I) Valves out of adjustment I) Readjust valves to proper setting

2) Engine does not draw fuel A) Air leak in fuel system and/or engine A) Replace fuel lines and/or tighten all engine bolts

B) High speed needle valve fully closed B) Reset high speed needle valve to factory setting

C) Low speed needle valve set too lean C) Reset low speed needle valve to factory setting

D) Fuel lines kinked D) Check and straighten fuel lines

E) Defective fuel tank E) Replace fuel tank

3) Engine vibrates excessively A) Propeller out of balance A) Balance propeller

B) Engine and/or engine mount loose B) Tighten engine mounting bolts

4) Engine does not transition A) Failed and/or wrong type glow plug A) Replace with new recommended glow plug

B) Old and/or wrong type fuel B) Replace with new recommended fuel

C) High speed needle valve set too rich C) Set high speed needle valve to leaner setting

D) Low speed needle valve set too lean D) Set low speed needle valve richer

E) Low speed needle valve set too rich E) Set low speed needle valve leaner

F) Air leak in fuel system and/or engine F) Replace fuel lines and/or tighten all engine bolts

G) Propeller too large G) Replace with one size smaller propeller

H) Valves out of adjustment H) Readjust valves to proper setting

5) Throttle barrel does not A) Throttle servo linkage out of adjustment A) Adjust throttle linkage to close throttle barrel

close completely completely

B) Idle stop screw out of adjustment B) Readjust idle stop screw to allow throttle to close

6) Engine overheats A) Engine running too lean A) Richen high speed needle valve

B) Cowl too restrictive B) Open larger vents in cowling to allow air to exit

C) Wrong type of fuel used C) Use fuel with recommended oil content

D) Engine not fully broken in D) Allow engine further break-in time

7) Engine stops abruptly A) Engine running too lean A) Richen high speed needle valve

B) Piston & sleeve out of tolerances B) Return engine to Global Services

C) Engine Overheating C) See # 6 above

This troubleshooting guide has been provided to help you diagnose and solve most problems that you may encounter with your XL RFS

series engine. Most problems encountered can be solved by carefully following the problem-cause-solution sections below. If you cannot

solve the problem using this troubleshooting guide, please feel free to contact us at the address or phone number listed below.

PROBLEM CAUSE SOLUTION

All Magnum engines returned for warranty service must be within the warranty terms as stated on the warranty card provided with your engine. Do not

return the engine to the place of purchase. They are not authorized or equipped to perform warranty work on Magnum products. When requesting

warranty service, please observe the following guidelines:

● Always send the complete engine including the carburetor and muffler. The engine must be removed from the model.

● Include a note detailing the problem or service you are requesting. Service cannot be provided without this information. Include your daytime

phone number in the event we need more details pertaining to the service requested.

● You may request an estimate of services at the time you return your engine for service. An omission of this request implies permission for the

Magnum Service Center to service your engine at our discretion.

● Include a method of payment for any service charges. If not specified, the unit will be returned to you C.O.D.

● Send the engine to us by United Parcel Service, Federal Express or by Insured Mail. Postage is not refundable. Send to:

Global Services ● 18480 Bandilier Circle ● Fountain Valley, CA 92708

Phone (714) 963-0329 ● Fax (714) 964-6236 ● Email: service@globalhobby.com

RETURNING YOUR ENGINE FOR WARRANTY SERVICE
12518 Intake Pipe & Cam Gear Cover Screw Set (2)

12819 Fuel Nipple w/Gasket12832 Idle Stop Screw w/Spring12833 Detent Spring12845 High Speed Needle Valve O-Ring12847 High Speed Needle Valve Holder Gasket12860 High Speed Needle Valve Assembly - Complete12861 High Speed Needle Valve Only - w/O-Ring12862 High Speed Needle Valve Holder - Complete40134 Backplate Bolt Set (4)46837 Rotor Bolt w/Gasket80110 Rear Ball Bearing80123 Head Bolt Set (5)80220 Propeller Washer Only80228 Propeller Washer & Nuts Set80231 Piston80238 Drive Washer & Collet80709 Cam Ball Bearing (1) - 2 Required80714 Cam Gear80719 Rocker Screw80732 Cam Bearing Cover Gasket80810 Low Speed Needle Valve80814 Carburetor Barrel Spring80816 Carburetor O-Ring80841 Split Washer80866 Throttle Arm160109 Front Ball Bearing80601A Muffler Assembly - Complete80801X Carburetor Assembly - Complete (No Intake Pipe)80-B Rocker Cover w/Screws80-C Intake Pipe Set w/Screws & Gasket80-D1 Exhaust Pipe w/Cinch Nuts80-E Muffler Only80-F Cam Bearing Cover w/Bolts80-H Intake Valve Set80-J Exhaust Valve Set80-K Rocker Arm Set91101FX Crankcase91102F Backplate91111F Backplate Gasket91112F Head Gasket Set91204F Connecting Rod91210F Crankshaft91213F Wrist Pin w/Retainer91232F Cylinder Sleeve91236F Piston Ring91-G1 Pushrod Assembly - 1 Set91-N Cylinder Head w/Valve Assemblies

RCRAFT

 LIST AND

NFORMATION
This maintenance information is provided to help you keep your new XL RFS series aircraft engine running in top form. Following this

maintenance information will ensure the long life and dependability you expect from your engine.

ADJUSTING THE VALVES

The valve clearances are preset from the factory, but do require periodic

adjustment. Reset the valves after the first 1 hour of engine run-time.

After that, the valves can be checked and adjusted about every 8 hours of

run-time. The valves will need adjustment if you notice a severe loss of

power or after you have repaired and/or reassembled the engine.

IMPORTANT Always adjust the valves with the engine cold.

❑ 1) With the engine cold, remove the rocker cover on top of the cylinder

head by unscrewing the two socket-cap screws.

❑ 2) Rotate the crankshaft until the piston is at top-dead center. Both

valves will be closed at this point.

❑ 3) The required valve clearance is between .04mm and .10mm,

measured between the valve stem and the rocker arm. Use feeler gauges

to check the clearance. The .04mm feeler gauge should pass through the

gap with only slight friction. The .10mm feeler gauge should be tight.

❑ 4) Working with one valve at a time, loosen the locking nut, using a

small wrench. Use a screwdriver to turn the adjustment screw

counterclockwise about 1/2 turn. This will open the gap slightly. Slide the

.04mm feeler gauge between the rocker arm and the valve stem.

Carefully turn the adjustment screw clockwise until the rocker arm touches

the feeler gauge. Using a small wrench, tighten the lock nut.

❑ 5) Remove the feeler gauge and double check the gap. Repeat step

# 4 if necessary to achieve the correct setting, then repeat the process for

the second valve assembly.

● Use a high-quality after-run oil in the engine after you have purged the

engine of fuel. Inject the oil into the engine through the carburetor and

through the glow plug hole. Rotate the crankshaft several times to

distribute the oil throughout the engine. This will prevent rust from

forming inside the engine, especially on the ball bearings.

● Wipe the outside of the engine dry using a soft cloth.

● Use a fuel filter between the fuel tank and the carburetor.

● Periodically check to make sure all of the engine bolts are tight,

including the muffler and exhaust pipe cinch nuts.

● Periodically check your fuel system, including the plumbing inside the

fuel tank, for leaks or cracks. We recommend changing the silicone fuel

tubing inside and outside the fuel tank at the start of every flying season or

about once a year.

● If you have attached a length of fuel tubing to the crankcase breather

nipple, periodically check the tubing for any blockage.

Long-Term Storage

If you will not be using your engine for a long period of time, such as

during the winter, we suggest you take the following precautions to

preserve the reliability of your engine:

● Run the engine completely dry of fuel as described above. This is

extremely important.

● Remove the rocker cover and cam gear cover and apply a generous

amount of after-run oil on and around the rocker arm assembly and the

cam gear. Reinstall the covers.

● Remove the engine backplate and apply a generous amount of

after-run oil to the engine crankcase and to the rear ball bearing, then

reinstall the backplate.

● Apply a generous amount of after-run oil to the joint between the

carburetor barrel and the carburetor housing to prevent the barrel from

sticking.

● Remove the glow plug and apply a generous amount of after-run oil

into the cylinder head. Reinstall the glow plug and turn the crankshaft

over several times to distribute the oil.

● Once that is done, place the engine in a sealed baggie and remove as

much air from the baggie as possible. Your engine can now be stored for

a long period without worrying about rust or engine degradation.

Resetting the Timing

XL .91RFS AIRCRAFT

ENGINE MAINTENANCE INFORMATION

MAINTENANCE

Engine maintenance should be done on a regular basis to ensure that you

keep the engine running in top form, especially over time. Following these

simple maintenance practices will ensure the long life and dependability

you expect from your engine.

● Avoid running the engine under dusty conditions. If you are in a dusty

environment, we suggest using an air filter over the carburetor.

● At the end of every flying day, purge the engine of fuel by disconnecting

the fuel line from the carburetor and allowing the engine to run dry of fuel.

The timing must be reset if the crankshaft and/or cam gear has been

disassembled. To reset the timing, rotate the crankshaft until the piston is

at top-dead center. (Verify this by looking through the glow plug hole.)

With the piston at top-dead center, install the cam gear with the small

punch mark facing toward you and pointing straight down toward the bottom of the crankcase. Reinstall the cam gear cover and tighten the screws.