Can’t say for sure but it looks like a cylinder from a late forties Evinrude Sportsman or Gale built motor. The cast in place cooling tube is the giveaway.
It will fit a model 4425 Evinrude Sportsman 1.5 horse built from 1948-51. Will fit other 1.5 hp motors built by Gale as Mumbles.
Hope this helps.
Best
PM T2
He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...