Sounds like those should be pointy needle points. Pointy tips always allow much wider and easier idle adjustment. Those rounded needles could be for HIGH speed adjustment only. No rules about which are adjustable.
Have a bad feeling about the carbs float setting. You need to find out if the carburetors are the correct ones for the engine FIRST. Start at the beginning of a unknown engine If carbs are correct then. Can you find any engine numbers on it ? Believe nothing anyone tells you.
Someone might post where the numbers are located on the engine.