Converse first thing you need is a viton tipped float needle, don't waste you time with the plastic ones, they just don't work (even the viton ones can be a bit problematic) The thing with the pull start "O" ring is if it is leaking you have lost suction and it will not draw fuel through the carb. It is obvious you have no fuel coming in because as you say the plug is dry. Only 2 things cause this float needle and the pull start seal, I have not come across one where the bottom seal was leaking. One other thing you must check is the main jet in the primer cap, you must be able to see cleanly through the strainer, I blow on them to make sure they are clear. As for the noise, they are all pretty noisy except for the Vortex I had, but it has an aluminium cover over the barrel and also it is fully enclosed inside the cowl and it has the CSIRO designed blade carrier that is also supposed to reduce the noise
