Just took my car out for a test drive with my new brake disc.. It cut out about 10 mins later, then wondered why it wouldnt start, then to realize that my high speed needle had snapped off the O ring next to the nut under the manual screw. How can i replace this? I took the nut off, but all that did was un screw the high speed needle. Please help D:

(I'm not too sure if it snapped, as there is an O ring, not usually O rings inside of solid metal with a small fuel inlet.. )