Topic: 1979 CB400T Petcock Question

[Patrick]

I managed to snap the nozzle off my fuel tank petcock. I'm having some issues finding another one from the same model bike and, I admit, I'm trying to cheap out on the replacement for now by not ordering a new $45 replacement. I was wondering if anyone can tell me if the petcock from another bike would fit? I know the nozzles come off petcocks in all directions, but I seem to have room to run the fule line in other ways than original. I was primarily wondering if anyone knows if the thread size and pitch of the connection on the tank is the same on other models of this or other vintages?

Thanks, in advance, for any help.

Patrick

[cb650]

Can you measure it?   I put a 79 650 petcock on my 360.  Had to T the line to feed both carbs but it works.



                     Terry

[Patrick]

The outer edge of the thread on the tank appears to measure 16mm - it actually was 15.86, but I can't guarantee that one of the teeth of my caliper didn't slide into a thread. I tried to measure lengthwise and it also was in the ballpark of 16mm (16.06), but I can't guarantee I was dead center on the connection. I couldn't find a nut that fit. What size did the 650 take?

Thanks,
Pat

[cb650]

Its 16 mm but didnt get the thread pitch.  Would imagine its the same.   If you look for a 650 petck you need a 79/80.  in 81 they changed the size bigger.



         Terry

[byidesign]

I remember when doing mine a few years ago that
   it was 16mm, but a strange thread pitch,
      so it would be hard to replace  from off the shelf.
          I ended up getting an oem replacement,
    as I use the bike daily, and you get the new
      filter screens with it.{I know it's a ripoff,
          but sometimes they "Gotcha" }
           Hope it helps
                   Bruce

[crazypj]

K&L supply list a replacement for CB400, its probably cheaper than OEM
PJ