If you want to locate sounds you can get a piece of hose like a 5/8 inch heater hose and hold it up to your ear and move it around the suspect area. It can help amplify the hissing.
On the choke nuts, WD-40 or soapy water would help them spin better and dry up later.
On the choke nuts, WD-40 or soapy water would help them spin better and dry up later.