I took the Nighthawk’s fuel petcock apart to clean it, and —after I was done— realized that I didn’t know how it goes back together. I checked the repair manual, Honda’s general service manual, and Google for assembly instructions, to no avail.
After some head-scratching, a fresh pot of coffee and some try-and-error assembly attempts, I finally figured it out. It’s not rocket science, of course, but I decided I should do my part to close this tiny little internet knowledge gap. So, here it goes:
This is a Keihin petcock from a 1992 Honda CB750 Nighthawk – all disassembled. By the way, this pile of scrap metal is worth a whopping $215 (check it out on BikeBandit).
Step 1 – The fuel strainer screen (the orange thingy): According to Honda’s maintenance schedule, it should be checked and cleaned on a regular basis.
Screen goes in first, then the rubber gasket and the “crap collector” (yes, that’s the technical term … I think 🙂 ).
In the photo below, the parts are lined up in the order they go together: left to right, top to bottom.
Step 2 – Membrane #1: First up, the metal ring and the smaller membrane. Make sure that the rubber membrane’s nipple (yes, I said nipple) is fully seated in the metal ring – you might have to push and wiggle it to get it where it needs to be.
Step 3 – Membrane #2: Next up is the piece that separates the two membranes. Make sure that the vacuum tube connector faces down (not up, like in this picture).
Then attach the larger membrane.
To attach the larger membrane to the other side of the metal ring, it might be easier to take it off the petcock (see image below). Again, make sure the membrane’s nipple is fully seated in the ring.
Note that the larger membrane has nipples on both sides. The bigger nipple faces down (attached to the metal ring), the smaller will face up.
Step 4 – The black disc: Put the black metal disc over membrane #2. Each side of the disc is different, but you’ll know which one is the right one when the hole in the disk lines up with the smaller nipple.
Step 5 – The spring: The spring goes next. It’ll seat perfectly in the black disc and the lid.
Step 6 – The lid: Make sure the lid and the spring line up.
Step 7 – Bolts: Screw in the bolts – done.
Knowledge gap: closed. World: saved.