DR,

Since the Webra is a tapered bore engine (ABN), the sloppy rich method is a no-no.
Read threads about break-in of such engines in old RCU and in Bill Baxter's OS support forum.

It is wrong and damaging to four-cycle such engine during break-in.

Slightly rich (+1/2-3/4 turn from peak RPM) for 15-30 minutes should be enough.
Then you can go full bore.

Only if you happen to fall upon a ringed Webra (it exists), should the four-cycle rich method be used.

The MVVS .49 is a better 3-D engine still.