O'Donnell SS .21 User Manual

1

ENGINE

E N G I N E

2

TABLE OF CONTENTS

Thank you for purchasing the O’Donnell SS .21 engine. Many years
of engine expertise were used to develop an engine with maximum
performance and reliability. This engine was manufactured using the
highest quality standards, materials and manufacturing processes.
When properly used and maintained, it will perform at the highest
level of racing. Carefully read through the entire instruction manual
before starting your SS .21 engine.

Safety Precautions .......................... 3

Important Information ...................... 4

Fuel ................................................. 5

Fuel Tubing ...................................... 5

Fuel Filter ........................................ 5

Air Filter ........................................... 6

Glow Plug ........................................ 6

Tuned Pipe ...................................... 7

Carburetor Restrictors ..................... 7

High Speed Needle ......................... 8

Low Speed Needle .......................... 8

Throttle Stop Screw ......................... 8

Factory Carburetor Settings ............ 8

Priming the Engine .......................... 9

Engine Break-In ............................ 10

Engine Maintenance ..................... 12

3

SAFETY PRECAUTIONS

• Model engine fuel is poisonous. Make sure you read and follow all
of the precautions on the fuel container.

• Keep fuel out of the reach of children.

• Model engine fuel is fl ammable and when ignited has a fl ame
that is diffi cult to see. Avoid sparks, fl ames, smoking or any other
ignition source when fuel is near.

• The engine emits harmful fumes just like a real vehicle. Do not

operate the engine indoors.

• The engine and its exhaust can become very hot during operation.

Avoid touching these parts during use and until they have cooled
down completely.

• The engine and exhaust produce quite a bit of noise. Do not run

your vehicle when or where it can disturb others.

• Avoid running the engine in cold weather. Running the engine in cold
weather can result in premature wear and poor performance.

4

IMPORTANT INFORMATION

• Make sure you properly tighten the fl ywheel/collet onto the engine.
We recommend using a fl ywheel wrench and a 10mm socket. DO
NOT put something in the exhaust to prevent the engine from
turning over.

• Make sure you keep your vehicles fuel tank free of dirt and debris.

• Make sure your vehicle’s clutch is in good working order before
installing it onto the SS .21. Periodically check your clutch to
ensure optimal performance.

5

FUEL

• We recommend O’Donnell 20% or 30%
racing fuel be used whenever possible. If
at any time during the life of the engine
you change fuel, either the percentage of
nitromethane or brand, we recommend
that you set the carburetor needles back to
the stock settings to help prevent possible
damage or premature engine wear.

• Whenever possible, do not allow the fuel
container to sit in direct sunlight or opened.
Always close the container promptly after
each use. Do not store on a concrete fl oor.
Doing so will decrease the quality of the
fuel and could cause the engine to perform poorly.

• We recommend that you install new fuel tubing on your vehicle
before installing the SS .21. This will help prevent problems related
to old or torn fuel tubing.

• We highly recommend a quality fuel fi lter be used between the
vehicle’s fuel tank and the SS carburetor. This will help keep out
dirt and debris that could be detrimental to the life of the engine.