i was wondering if it is necessary to put foam inserts in these tires as it will be used primarily for back yard use

If memory serves me correctly, the stock wheel and tire combo did not come with foam inserts. The Hornet followed the Sand Scorcher, Rough Rider and F-150 that did not use inserts either. I don't think foam inserts came about early '90s. Your Hornet was introduced more in the '84-'85 time frame. You may want to post your question in the R/C car section, there may be someone with better memory in that section.

there was no foam or foam in the wheels, I have a Boomerang (Saber) in 1986.
Yes, and my son works in "Tamiya" an official dealer in Russia.
He knows EVERYTHING about it

thanks these tires will be going on a radio shack golden arrow and the tires mentioned foam so i wasnt sure what to do thanks