1980 kz440b stock muffler packing question

Hello,

I am doing some fine tuning on my 1980 kz440b scrambler build. Im chasing down the correct jetting and have started backfiring. In my search for solutions, including exhaust leaks, I pulled my baffle out to inspect. There is no packing, wondering if this style of baffle gets packed; I am more familiar with perforated tubes. When I started the bike up last week after sitting for three years, a squirrels nest and some acorns shot out. I didn't look if it was old packing material, or something they brought in. Many thanks, pictures attached.

 

I don't think Kawasaki used any packing material. typically the baffles are just steel tubes. some are more complex than yours.

aftermarket baffles are available.