Author Topic: Tracking down correct petcock  (Read 899 times)

Offline jasonxdooley

  • Posts: 1
Tracking down correct petcock
« on: Sep 30, 2018, 12:10:20 »
Hey, hoping for some help / pointers here...

Background: I have an 81 cb750K with what I think is a tank from an 80s cb750f or 900f that the previous owner had installed. The original petcock was present when I first got the bike, and replaced with a cheap aftermarket that's never worked very well.

I purchased an OEM petcock (16950-MA4-671) which is supposed to be for the 81 750k and possibly some of the 900 series, but it doesn't fit the seal on the tank connector.

The aftermarket petcock diameter of the filter is 8mm, while the diameter of the OEM petcock filter is 10mm.

I don't know if I should be looking at the OEM petcock 16950-461-771 or if anyone has any insight, it would be greatly appreciated.

Including a shot of the tank and the petcocks (aftermarket on left (bottom) / oem on right (top))

Offline pidjones

  • Posts: 841
Re: Tracking down correct petcock
« Reply #1 on: Sep 30, 2018, 22:10:56 »
I have a '79 CB750F with filter diameter of 10mm. I had a similar issue trying to fit a new OEM petcock filter to the oldest daughter's 750 Shadow. Turns out the hole was just cruded up with rust, shrinking the hole down. Judicious poking and prodding opened the hole back up so it could be installed. I think maybe the aftermarket guys know of that problem and make theirs smaller because of it. Of course it won't flow as well.
"Love 'em all.... Let God sort 'em out!"

Offline irk miller

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Re: Tracking down correct petcock
« Reply #2 on: Sep 30, 2018, 23:50:04 »
Not sure of your issue, but I will say the OEM petcock has a larger nipple, which is what I would be focused on.  If your OEM filter is not fitting in the tank, be sure the original filter isn't stuck in the tank.  It can be hard to tell when they're jammed up in there.  Otherwise, like pidjones is suggesting, make it 10mm if you can.