O'Donnell SS .21, Manual

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11
Tanks 1-4: Start the engine and run the vehicle approximately 100
feet back and forth or in a fi gure eight. Do not squeeze the throttle
more than 1/2-way. Every 4-6 passes check the engine temp
making sure that it does not go over 170° Fahrenheit. Continue this
procedure for the fi rst four tanks, making sure you do not allow the
engine to run out of fuel.
Tanks 5-6: Continue running the vehicle approximately 100 feet
back and forth. Now you can squeeze the throttle 3/4 of the way.
Continue to temp the engine every 4-6 passes, making sure that
the engine temperature does not go over 190° Fahrenheit. After
tank 6 you are ready to fi ne tune in your engine. After tank 6 allow
the engine to cool down. Then restart the engine.
Tanks 7-8: You can now run the vehicle approximately 150-200
feet, pulling the trigger to full throttle the last 50 feet of each pass.
Continue to temp the engine every 4-6 passes, making sure that
the engine temperature is close to 200° Fahrenheit but no more
than 210° Fahrenheit.
During tanks 7-8 bring the vehicle to a stop and allow it to idle for 10
seconds. Then pull full throttle for approximately 100 feet. Take note
of how much smoke comes out during acceleration. Optimum is a
small amount of smoke from stop to approximately 100 feet. Once
this is achieved do the same thing only go 150-200 feet. Continue
to check the engine temperature every 4-6 passes. The fi nal head
temp after break-in should be approximately 210° Fahrenheit.
After the 8th tank, your engine should be ready to race. Additional
tuning may be necessary at the track for optimal performance.