Originally posted by Britbodger: Just as a more extreme example of breaking-in an engine:
On a fresh rebore and new pistons and rings started for the first time and broke-in my T120 with Routt barrel and MAP billet pistons during practice sessions at a road race meeting last year. At the end of the practice sessions (about 25 miles) had the throttle wide open and, of course, in my races as well.
Should mention that the bore was expertly honed with torque plate to the correct finish (by Marino's brother Terry) for ductile steel rings with 5.1/2 thou piston to wall clearance.
A subsequent strip-down revealed the bore and pistons and rings to be in good condition with evidence of good ring seating. Pistons did have slight scuff marks.
Course may have shortened the life of the cylinder, pistons and rings using this procedure but just trying to illustrate that high rpm doesn't necessarily result in seizure - admittedly with genorous piston to bore clearance.
P.S. Also should mention that I took the precaution of using Aviation Shell 100 (50w) for the break-in as it was very hot at that particular track at Albuquerue New Mexico
That method works and you pretty much have no choice safety wise, good to walk around the pits and warn folks that you may be a little slow in the first practice sessions.
John H, I once tried to bump start a Z1000 superbike [10:1] on dry bores, the old Kawas would not select 2nd unless the crank was spinning and no way we could get it to turn over, had to put a half teaspoon of R Synthetic down all plugholes.
I wish I still had that bike.