The oil makes the seal at the main bearings. While most of my prewar motors run on 3 oz. of oil Per.gal. it depends on the condition of the motor. Go back to 16 to 1. Get one of these drill adapters and using a socket try to start the motor using a drill. Start with the mixture screw closed all the way. Then open it slowly while you have the motor spinning till it starts. This will get the oil back into the bearings. After you get it running well, should you decide you would like to reduce the amount of oil, try the amount you’d be comfortable with. If it becomes harder to start, or begins running poorly, especially at slow speed, you need more oil to maintain that seal at the main bearings. Take off the carburetor. Remove the float bowl, poppet valve cover, poppet valve, and mixture screw. Over a clean paper towel, back flush it through the mixture screw hole with wd40, silicone spray, carb or brake cleaner, whatever you have and check the towel for dirt. Even if your tank has a screen filter this stuff get through. Whenever you’re having running problems, you should check for dirt. It will likely take awhile before you get the fuel system really clean. Its a small passage that the fuel runs through and the slightest bit of dirt in there can really affect how a motor runs. If you’re only getting a spark in the position shown, remove the flywheel. Move the magneto plate back and forth looking for where a wire could be broken or grounding out. Take a good look at those dried out plug wires where they pass through the magneto plate. The magneto in your picture is in the correct position for starting. Even a little more to the right, about 4 o’clock, might be helpful to get it started.