[oil pan 4]

I gave up on trying to tune the epa approved carb it came with. I got a cheap knockoff. The log splitter fuel tank is full of E10 gutter swill. Took the epa pos and S canned it. Main thing the epa approved carb lacked was an adjustable air bleed after the throttle. So I set the air bleed at the obligatory 2 and a half turns from being closed.
The replacement carb appears to have a bigger fixed air bleed orifice. Its the little black plug held in place by being located under the idle speed screw.
The epa approved air bleed plug is smaller allows a more rich air fuel emulsion to be drawn into the engine at part throttle, that's one reason it was running so rich. I believe it's like a holley power valve. The knockoff has a bigger fixed air emulsion orifice which allows a leaner air fuel mix to form for idle and part throttle run.
The knock off carb had an unlabeled main jet. It was definitely bigger than my #65. It appeared to be about a #72. Stsrted off by putting the #65 in there, it didn't want to stay running with the choke open.
The next size up from a #65 but smaller than the unlabeled stock jet was a #69. Put the #69 in and it stated up, didn't want to stay running without a little choke. Ran great once warmed up with the WAI cover on.
When splitting a knot it sputtered a bit.
So running E10 it's a bit lean. Switching to ethanol free gas should richen it up a bit and I can fine tune it with the adjustable air bleed screw.
As long as that sputter at full speed WOT is eliminated it will be just about perfect.
To shut down I turn the fuel off and idle it to cool. Its idling significantly longer. I know it a different carb and all, so it might hold a bit more fuel or have the fuel draw from a mm or 2 lower in the bowl, maybe. But it's definitely idling leaner, it doesn't sink like gas at idle.