Once it warmed up and i kicked the choke off, it was down around 20psi at a low idle. Yippee! I ran it for 15 minutes, drained it, tossed the filter, and replaced with 3.5 qt motor oil, 1 qt Marvel Mystery Oil. The concoction I drained was dark brown, but not overly black. I ran this second concoction through, with about the same PSI numbers.