No. Drilling the crank is definitely NOT the correct course of action. Contacting the B & S rep is the way to go. Allowing B & S to trace the issue back to its source will address the issue properly. And, you’ll get a new engine for your efforts.
If you go back & read the whole post you will note this was purchased in job lot of broken mowers at auction
So the inference would be that a warranty claim had already been made on it and what was supposed to go for scrap metal managed to end up at auction .
These have become very poplar down here as importers have no repair facility so they recoup some of the warranty losses by selling the returned goods by the pallet load as "defective returns " if the auction house is honest or "untested " if the auction house is less than honest .
some of the electronics geeks make a fortune repairing defective TV's many of which have nothing more wrong than a loose card or a badly soldered joint
A friend got a whole pallet load that had nothing more wrong than blown fuses which are now inside where the owner can not access them