This is how I now " run in " new engines.
Put on helmet & gloves.
Start bike using starter fluid is necessary.
If the engine can be made to run jump strait on and "ride like I just stole it"
One lap of the block, about 1.5 mies and the engine is "run in".
Return home, adjust carb allow engine to cool down.
Check cylinder bolts reset the tappets readjust the carb.
Test ride around same block.
return readjust carb if necessary, change oil.
Bike is now ready for 20,000 miles.
I used to mamby pamby it, leave it on idle for ages while adjusting valves & check all the other stuff by which time the rings had aready glazed in the bore and made a bypass route strait down to the cases.
Some long discussions when mr Healey changed my ideas and I have never had a new engine fail yet as comparred to about 1 in 5 previously,
All engines rebuilt this way have given long trouble free service lives.