Acording to my repair manual,ca;1978
PROPER BREAK-IN IS IMPORTANT/BREAK-IN PROCEDURES
Fast idle until normal temp is reached
As soon as the engine is started,set the idle adjustment to produce an engine speed of around 1,200 rpm.this will insure
a good oil pressure and throw-off will be sufficient to lubricate
adequately the cylinder walls. operate the engine at this speed until normal operating tempature is reached(usually 15 to 20 minutes.
If for some reason it was not possible to pressurize the lubrication system before starting the engine,a few squirts of
engine oil should be directed into the carburetor air horn during the first minute or two of operation. This will provide cylinder lubrication until bearing throwoff and "split hole"lubrication takes over.
Check oil pressure and coolant temperature occasionally during warmup.Check coolant level as there may have been air in the system when filling.Inspect for any signs of gasoline,oil or coolant leakage.
