Author Topic: Repairing riveted petcocks  (Read 4171 times)

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Offline Jay B

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Repairing riveted petcocks
« on: May 16, 2008, 07:15:34 AM »
My brothers dohc 750 started leaking around the petcock handle. I resurected it for him after being stored for 20 years. It has the same non servicable riveted petcock as the newer sohc's. I found a new valve seal on eBay for $8 including shipping. The ears that the rivets go into on the valve body are made such that you can drill straight through them. Went to the hardware store and found the smallest machine screws and nuts I could find and a bit to match. I drilled off the rivet head and removed the faceplate and internals. Then I drilled through the ears on the body and put it back together with the nuts on the back side. Worked great and now it's servicable in case it ever needs freshening up again.
Jay
'77 CB550K
'74 CB350F cafe
2001 Road King
'73 CB175



Offline Jay B

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Re: Repairing riveted petcocks
« Reply #1 on: May 16, 2008, 07:18:16 AM »
BTW, if anyone wants to try this, search eBay for "honda fuel valve". For some reason the seller doesn't mention petcock in description and it wont come up searching petcock. He says the seal is "about 20mm" That's the one.
Jay
'77 CB550K
'74 CB350F cafe
2001 Road King
'73 CB175



Offline 750essess

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Re: Repairing riveted petcocks
« Reply #2 on: May 27, 2008, 01:50:32 PM »
I did the same thing to my 79cb750, 'cept I tapped the holes. Those petcocks are stupid expensive, and your trick is a great way to save one
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Offline BobbyR

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Re: Repairing riveted petcocks
« Reply #3 on: June 03, 2008, 06:52:54 PM »
A real old school trick is to remove the seal and turn it over. The back is smooth and unworn.
But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?



gasshog2

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Re: Repairing riveted petcocks
« Reply #4 on: September 02, 2008, 08:42:59 PM »
Since it was a non servicable riveted petcock how did you know what valve seal would work?  I have a 1978 750K and it leaks when going from OFF to ON and ON to OFF.  Would love to know which valve seal to buy.  Thanks 



Offline cb750k7

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Re: Repairing riveted petcocks
« Reply #5 on: September 02, 2008, 10:49:22 PM »
Since it was a non servicable riveted petcock how did you know what valve seal would work?  I have a 1978 750K and it leaks when going from OFF to ON and ON to OFF.  Would love to know which valve seal to buy.  Thanks 


+1

Thanks,

Jona
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Offline TwoTired

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Re: Repairing riveted petcocks
« Reply #6 on: September 03, 2008, 01:01:07 AM »
I rebuilt my 78 Cb750F petcock, drilled the "rivet" and tapped the housing and used this gasket.  One done one to go.

Cheers,



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

Popeye: "Wrong is wrong, even when it helps ya."



Offline cb750k7

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Re: Repairing riveted petcocks
« Reply #7 on: September 09, 2008, 10:51:09 PM »
I rebuilt my 78 Cb750F petcock, drilled the "rivet" and tapped the housing and used this gasket.  One done one to go.

Cheers,





Hi,
Is it the gasket to be replaced?


TNX

Jona
Found real friends here !!!



Offline TwoTired

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Re: Repairing riveted petcocks
« Reply #8 on: September 10, 2008, 12:07:57 AM »
yes
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

Popeye: "Wrong is wrong, even when it helps ya."



gasshog2

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Re: Repairing riveted petcocks
« Reply #9 on: September 13, 2008, 05:44:53 PM »
Today I decided it was time to attempt to repair my 1978 750K's leaky petcock.  The face plate is not actually riveted on.  The body is casted with bosses that acts as rivet to hold the face plate on.  I removed the head of the so called rivet using a large drill bit turning it by hand.  I removed just enough of the head to get the face plate off. Then with a file I cleaned them up so the face plate would fit over them with ease.  Now for the tricky part,  you better use a drill dress, I drilled #36 holes through the center of the bosses (no room for error here, very little edge margin).  I drilled them approx. 3/8" deep.  Tapped the holes using a 6-32 tap.  Pickup (2) 1/4 long 6-32 SS pan head screws and using  the Honda OEM gasket 16955-268-020 as suggested by TWOTIRED I reassembled all the parts.  Works great..... Thanks to TWOTIRED....



ev0lution7

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Re: Repairing riveted petcocks
« Reply #10 on: September 23, 2008, 02:09:30 PM »
i did mine this way as well works great! i just took my time with the tap and it work! i'm realy happy to have a rebuildable petcock now! specially if you look around on ebay and find only NEW petcocks for $50+ way nice for about $10 fix!



Offline sohc4Lat

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Re: Repairing riveted petcocks
« Reply #11 on: May 04, 2011, 06:19:01 PM »
Thanks Lloyd, et al! My petcock was not leaking and all three functions still worked, but she would cut out or hit a flat spot with no recovery or rpm climb in 5th. Must have been sucking air into the fuel delivery. All that is history now! Thanks for the heads up, folks!

Too bad I didn't get her fixed before I rode her from Dallas to Houston this last weekend, but that is a whole nother story! She got me there and back. Yep, now I am bragging!!! The '05 BMW GS was taking  a dead battery nap! ~Jeff




Offline rocketritch

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Re: Repairing riveted petcocks
« Reply #12 on: March 06, 2012, 06:46:39 PM »
Anyone know if this gasket will work for a 1982 Nighthawk 750?



Offline DWS

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Re: Repairing riveted petcocks
« Reply #13 on: September 28, 2012, 03:15:50 PM »
thanks for the tip. i need to do this now, i was going to drill out the rivets cause that was the only thing i could do next without buying a new one but now i can buy the seal that i need. thanks
Always looking for friends
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BSA MX 50 Next
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Offline TwoTired

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Re: Repairing riveted petcocks
« Reply #14 on: September 28, 2012, 03:32:17 PM »
While doing refurbish on the GL1100, I found these petcock repair gaskets made in Viton rather than the rubber Honda uses.  Rubber was fine for non-ethanol gas.  But, elected officials/agencies removed that choice for many of us.  Viton withstands ethanol.

http://www.randakks.com/Carb%20Parts.htm#13A

GL1000 / GL1100 Petcock Repair Kit
    Item # GLPETRK01

http://www.randakks.com/Petcock1.jpg

They are $16.  But, I know of nowhere else to get them in Viton.

Cheers,
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

Popeye: "Wrong is wrong, even when it helps ya."



Offline DWS

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Re: Repairing riveted petcocks
« Reply #15 on: September 28, 2012, 03:55:13 PM »
thanks do myou have any idea where to get  parts for my cb750 1978 f3 PD42A carbs. some doc saids its suppose to be PD42b and there not whats up with that? bought the bike new in 1978
Always looking for friends
78 Honda CB 750 F3 Restoring now
BSA MX 50 Next
BSA b50T Parts
Yamaha 1980 Virago 750 thinking about restoring maybe parting



Offline TwoTired

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Re: Repairing riveted petcocks
« Reply #16 on: September 28, 2012, 04:23:24 PM »
thanks do myou have any idea where to get  parts for my cb750 1978 f3 PD42A carbs. some doc saids its suppose to be PD42b and there not whats up with that? bought the bike new in 1978


What parts?
Have you tried sirius?  There are parts suppliers listed in the FAQ.

This chart says you have the correct carbs on your bike:
http://www.motorcycleproject.com/motorcycle/text/specs.html
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

Popeye: "Wrong is wrong, even when it helps ya."



Offline DWS

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Re: Repairing riveted petcocks
« Reply #17 on: September 28, 2012, 08:20:48 PM »
thank you for the chart (TwoTired ) one of the PDF files i down loaded said it should have been PD42A but now i feel better that you showed me the deference. the jets in the carb is 110 though

Always looking for friends
78 Honda CB 750 F3 Restoring now
BSA MX 50 Next
BSA b50T Parts
Yamaha 1980 Virago 750 thinking about restoring maybe parting