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Offline rk

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Stripped Bung
« on: August 27, 2015, 12:44:48 PM »
As the title states... I stripped my bung whil I was in a hurry. The peacock I finally found (apparently mine is a weird size) had the wrong thread pitch... And in haste I totally stripped the bung. And now it leaks...

Any ideas? Some special glue? Tap and die?

I don't have a welder... So that's not in the cards. Help!
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1975 CB400F (First bike - learning lots)

- Podded
- Dyna S ignition
- Yoshima Exhaust
- bored to 473cc or 466cc... or something. Maybe someone can correct me
- #82 mains, #42 pilots

Offline calj737

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Re: Stripped Bung
« Reply #1 on: August 27, 2015, 12:52:34 PM »
the petcock bung on the underside of the tank? If so, a die nut in HSS with the correct pitch will do the trick. Match it to your petcock pitch for best results. Or repair and get the proper petcock.
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Offline 754

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Re: Stripped Bung
« Reply #2 on: August 27, 2015, 01:57:04 PM »
If you can't find threads, maybe you can tap for NPT.... Not sure though.
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Maker of the WELDLESS 750 Frame Kit
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Offline Vinhead1957

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Re: Stripped Bung
« Reply #3 on: August 27, 2015, 02:17:30 PM »
Teflon tape and the correct pitched petcock. If you are careful, it may find the correct course
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Offline 754

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Re: Stripped Bung
« Reply #4 on: August 27, 2015, 02:43:54 PM »
How do you strip a steel bung with a brass nut..maybe a threadfile can fix it.
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline przjohn

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Re: Stripped Bung
« Reply #5 on: August 27, 2015, 03:19:48 PM »
I have used a small hacksaw blade on one that came back from the painter damaged. Just take your time and find the top thread that is causing the problem and correct it with the saw, easily filing out the bad thread. If you have, "Experienced" eyes like mine a magnifying glass helps. This can only be done of course if you didn't loose patience with it and force it to cross thread the other threads.
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Offline 754

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Re: Stripped Bung
« Reply #6 on: August 27, 2015, 03:23:39 PM »
 ? Hacksaw?

 Try a three corner file.. It actually fits the thread profile..
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline przjohn

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Re: Stripped Bung
« Reply #7 on: August 27, 2015, 03:35:20 PM »
Quote from: 754 on August 27, 2015, 03:23:39 PM
? Hacksaw?

 Try a three corner file.. It actually fits the thread profile..

I find the small blade fits right in the valley of the thread and can follow it around. All you need to do is clear the thread, but I will try that next time, just need to get a file like that.
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I like poetry, long walks on the beach, and poking at dead things with a stick.

Offline rk

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Re: Stripped Bung
« Reply #8 on: August 30, 2015, 07:00:02 PM »
I've been spending some time with it this weekend... It looks like the steel threads on the bung are okay... The Pingel nut I had on it is definitely toast though. I had tried epoxy to try and seal it but it leaked... And made a mess.

So... I guess the next question is... Anybody familiar with a 20mm fuel petcock? I've been looking a lot with no luck aside from this Pingel nut... Right size, wrong thread pitch.
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1975 CB400F (First bike - learning lots)

- Podded
- Dyna S ignition
- Yoshima Exhaust
- bored to 473cc or 466cc... or something. Maybe someone can correct me
- #82 mains, #42 pilots

Offline 754

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Re: Stripped Bung
« Reply #9 on: August 30, 2015, 07:05:57 PM »
If it's 20 x 1.5.mm the pitch is close to 16 tpi.. If you are tying to clean threads in the nut, but that one sounds too far gone
 Does nut come off.? Pingel may be able to get you a replacement.
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Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way
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