Never put a drop of fuel with ethanol in a 2 cycle engine it destroys the fuel lines, gaskets, etc. i use 93 octane ethanol free with stihl synthetic 2 cycle oil!
Go down south hwy 225 and see Stan Fleming he's a go too guy on chevy engines, he is on the left before Cananland Christian School in a block building 770 709 8517
Check & see if you happen to have the old filter that you took off check it for a missing O ring that sometimes gets stuck to the engine block causing an oil leak, i hope it's not a big problem. Mike