Author Topic: 1978 CB750F PETCOCK  (Read 4649 times)

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Offline cafeconleche

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1978 CB750F PETCOCK
« on: February 11, 2009, 02:10:02 PM »
As I have come to learn, these buggers are hard to come by.

Where can I find an aftermarket one, or does anyone know if any other petcocks that definitely have the same threading?

I just don't want to continue the guessing process.

Thanks,

Jake

Offline Bido

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Re: 1978 CB750F PETCOCK
« Reply #1 on: February 13, 2009, 08:09:25 AM »
I have asked the same question and no one seems to have an answer. I bought a used one on E-Bay rebuilt it but I sure would like to know if any other year or model was interchangble or if there is an aftermarket resource.

Bido
1978 CB750 Supersport F3
1981 CB750 K

Offline Alan F.

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Re: 1978 CB750F PETCOCK
« Reply #2 on: February 14, 2009, 08:35:20 PM »
The 77 CB750F used the same petcock, p/n 16950-410-015, and the 79 and 80 models uses one with a similar configuration and outlet routing, but I can't tell you if it'll thread on.

Offline bwaller

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Re: 1978 CB750F PETCOCK
« Reply #3 on: February 14, 2009, 09:29:05 PM »
I expect the F model uses the same packing, at least it's worth a look.

I posted this a few years back under petcock repair http//forums.sohc4.net/index.php?topic=14938.0
« Last Edit: February 15, 2009, 04:42:37 AM by bwaller »

Offline cb750fbomb

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Re: 1978 CB750F PETCOCK
« Reply #4 on: February 14, 2009, 10:23:19 PM »
I expect the F model uses the same packing, at least it's worth a look.

I posted this a few years back under petcock repair //forums.sohc4.net/index.php?topic=14938.0

My petcock doesn't have screws. It's riveted together. No rebuilding that unless there's a trick. It look's just like the one in the petcock repair thread except for the screws.
'77 CB750F2
“The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.”

Offline Finn

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Re: 1978 CB750F PETCOCK
« Reply #5 on: February 14, 2009, 11:09:23 PM »
Quote
As I have come to learn, these buggers are hard to come by.

Where can I find an aftermarket one, or does anyone know if any other petcocks that definitely have the same threading?

I just don't want to continue the guessing process.

Thanks,

Jake

Hey Jake,

I just got my '78 F a few days ago.  The guy I bought it from let me in on the fact that these petcocks apparently just don't exist.  The one on there now (and apparently there to stay) was something he had pack-ratted away from a different bike.  It's fresh and clean and works, but the fuel line is rerouted.  I'll give the guy a holler and ask exactly what it is.

 :)

~ Finn

The best way to learn it is to do it!

Offline TwoTired

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Re: 1978 CB750F PETCOCK
« Reply #6 on: February 14, 2009, 11:58:39 PM »
I expect the F model uses the same packing, at least it's worth a look.

I posted this a few years back under petcock repair //forums.sohc4.net/index.php?topic=14938.0

My petcock doesn't have screws. It's riveted together. No rebuilding that unless there's a trick. It look's just like the one in the petcock repair thread except for the screws.

See:
http://forums.sohc4.net/index.php?topic=34758.msg413245#msg413245
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline cb750fbomb

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Re: 1978 CB750F PETCOCK
« Reply #7 on: February 15, 2009, 12:31:54 AM »
I expect the F model uses the same packing, at least it's worth a look.

I posted this a few years back under petcock repair //forums.sohc4.net/index.php?topic=14938.0

My petcock doesn't have screws. It's riveted together. No rebuilding that unless there's a trick. It look's just like the one in the petcock repair thread except for the screws.

See:
http://forums.sohc4.net/index.php?topic=34758.msg413245#msg413245
Thanks, TwoTired. I don't have the tools to tap the housing, but now I may have to track down some pricing.
'77 CB750F2
“The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.”

Offline cafeconleche

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Re: 1978 CB750F PETCOCK
« Reply #8 on: February 15, 2009, 09:04:56 AM »
Quote
As I have come to learn, these buggers are hard to come by.

Where can I find an aftermarket one, or does anyone know if any other petcocks that definitely have the same threading?

I just don't want to continue the guessing process.

Thanks,

Jake

Hey Jake,

I just got my '78 F a few days ago.  The guy I bought it from let me in on the fact that these petcocks apparently just don't exist.  The one on there now (and apparently there to stay) was something he had pack-ratted away from a different bike.  It's fresh and clean and works, but the fuel line is rerouted.  I'll give the guy a holler and ask exactly what it is.

 :)



Thanks, it would be much appreciated.

Offline cafeconleche

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Re: 1978 CB750F PETCOCK
« Reply #9 on: February 15, 2009, 03:54:45 PM »
Today I took the petcock off my 77 750k tank and it fit on the 78 750f tank, I was sooooooo psyched, now all i have to do is rebuild it because it leaks like a siv

Offline mattcoff1

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Re: 1978 CB750F PETCOCK
« Reply #10 on: February 15, 2009, 07:01:10 PM »
Hello
I found out after trying to find a petcock for my 78 k
that... you can get them for an auto matic the fuel outlet is 90degrees different but thats all just turn the new petcock 90 degrees

 Matt

Offline Finn

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Re: 1978 CB750F PETCOCK
« Reply #11 on: February 16, 2009, 09:55:07 AM »
Hey Jake,

Sounds like you got the problem licked, but for follow up here's what the PO said:

The 77-78F has a 16mm Bung (I did not know that's what that's called) instead of 14mm like everything else.  The only one he could find that had the 16mm was from Honda for a CX650 circa 78-81.  He ordered it new from Honda.  Again, the fuel line is rerouted but works great.  It's also kinda fly looking 'cause he used transparent yellow tubing that is now a little more exposed from the rerouting.

See ya,
~ Finn

The best way to learn it is to do it!