Doug:

If you are saying a piston baffle is not needed to run this engine you are in error. It is "Loop scavenged," without the baffle on the piston it will run poorly, if at all.

Bonehead's engine, with a chunk of the baffle missing will probably run, but it would run better if it were complete.

Now if you are referring to a muffler baffle, you are right. It will also run with no muffler at all.

Bill.