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Author Topic: Petcock issues  (Read 1555 times)

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Offline socalenduro

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Petcock issues
« on: March 16, 2011, 09:26:45 PM »
In taking my petcock apart to rebuild it and stop the leaking.....

Is this brass pipe in the middle supposed to be longer? it looks like it might be broken off, and in the instructions the illustration shows a much longer length

If it is broken is this something i need to be worried about?


« Last Edit: March 17, 2011, 05:19:56 AM by socalenduro »
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Offline TwoTired

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Re: Petcock issues
« Reply #1 on: March 16, 2011, 09:31:55 PM »
That is supposed to be a tube about 1 1/2 or 2 inches long.  It is (was) the stand pipe for mains feed of fuel.  When the fuel level gets below that, then reserved is selected which feeds from the bottom of the tank.  The way yours is missing, means you have no reserves to select.  Both on and res drain fuel from the bottom.

Cheers,
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Lloyd... (SOHC4 #11 Original Mail List)
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Offline socalenduro

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Re: Petcock issues
« Reply #2 on: March 16, 2011, 09:34:32 PM »
which explains me running out of gas....and reserve not helping out

so while it is broken it really does not need to be fixed as long as i know i have no reserve?
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Offline midnightrider

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Re: Petcock issues
« Reply #3 on: March 16, 2011, 10:19:58 PM »
Quote from: socalenduro on March 16, 2011, 09:34:32 PM
which explains me running out of gas....and reserve not helping out

so while it is broken it really does not need to be fixed as long as i know i have no reserve?
Yep.  Don't let your gas get low!
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Offline TwoTired

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Re: Petcock issues
« Reply #4 on: March 16, 2011, 11:54:23 PM »
Quote from: socalenduro on March 16, 2011, 09:34:32 PM
which explains me running out of gas....and reserve not helping out

so while it is broken it really does not need to be fixed as long as i know i have no reserve?

Well, yes.  But, you can get brass tubing as most hobby stores, and jam a new tube in the old hole.  Just drill an interference sized hole (close to same size as tube.)

Cheers,
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Lloyd... (SOHC4 #11 Original Mail List)
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Offline RickB

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Re: Petcock issues
« Reply #5 on: March 17, 2011, 02:55:40 AM »
Hey mate,

I had the exact same problem you did for by 350F petcock.

http://forums.sohc4.net/index.php?topic=51957.msg949719#msg949719

I replaced it with 5mm brass tubing I found at a hobby shop. It was the only place that had it that small. Don't even waste your time looking somewhere else. I did it for you!

Sorry TwoTired, I disagree with you about the drilling. The tube is recessed into the aluminum with no seal or anything. There's no hole to drill so to speak. Just use some needle nose pliers to pull the old one out, with a file bevel the end to be inserted, then press the new one in there. Read my post above for an excellent eBay seller offering fantastic 350F petcock rebuild kits.

Rick.
« Last Edit: March 17, 2011, 03:34:21 AM by RickB »
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bollingball

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Re: Petcock issues
« Reply #6 on: March 17, 2011, 03:17:14 AM »
If you put a new one in take a fine file and bevel the end slightly blow off all filing. I had to cut mine shorter PO had changed it I had a 3 gallon reserve :D
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Offline dhall57

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Re: Petcock issues
« Reply #7 on: March 17, 2011, 03:21:13 AM »
 Don't mean to jump in on your thread, but talking about petcocks, on my 750K6 the owners man. says to clean the petcock filter at times to be sure fuel is flowing freely. I took mine apart and didn't see any type of filter or screen. All I saw was a small rubber type gasket with a couple holes in it. I cleaned everything good and put it back together. But where's the filter. I notice the K6 petcock is a little different design than the early 750's.
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Offline RickB

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Re: Petcock issues
« Reply #8 on: March 17, 2011, 03:35:17 AM »
bollingball you're right, you have to bevel the end to be inserted. I forgot to mention that but have amended my original comment.
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Offline RickB

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Re: Petcock issues
« Reply #9 on: March 17, 2011, 03:39:26 AM »
dhall57,

I had the same thing with my 350F petcock. I bought it over ebay and it was in terrible condition. When i pulled the bowl off, it was full of a goop that I can only assume was old fuel and o-rings.

There wasn't a screen filter or o-rings. I imagine that if it didn't dissolve, it would have been the first thing to fall out had someone unscrewed the bowl without being careful. Probably what happened to yours. Buy a rebuild kit. Not worth getting bits of rust from your tank or whatever into your fuel supply.

Rick.
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Offline TwoTired

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Re: Petcock issues
« Reply #10 on: March 17, 2011, 11:10:55 AM »
Quote from: dhall57 on March 17, 2011, 03:21:13 AM
Don't mean to jump in on your thread, but talking about petcocks, on my 750K6 the owners man. says to clean the petcock filter at times to be sure fuel is flowing freely. I took mine apart and didn't see any type of filter or screen. All I saw was a small rubber type gasket with a couple holes in it. I cleaned everything good and put it back together. But where's the filter. I notice the K6 petcock is a little different design than the early 750's.
You don't have a working reserve either, right?

Anyway, you have a different fuel tap design than the one being discussed in this thread.  Yours, has had the filter and stand pipe assembly removed by some cheap/dumb p.o.

You need to buy and install part Number 3 as depicted here:
http://www.cmsnl.com/honda-cb750k6-four-usa_model14380/partslist/F12.html

Cheers,
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Lloyd... (SOHC4 #11 Original Mail List)
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Offline socalenduro

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Re: Petcock issues
« Reply #11 on: March 19, 2011, 04:33:25 PM »
ok so i went to the hobby shop and got a #129 pipe that looked great....
with a lil heat got the old pipe out and of course the #129 fits in but isnt tight and has the tiniest about of play...
went back and got a #130 pipe.... too thick even after beveling and sanding away quite a bit

ideas? tips? help i want to ride tomorrow!
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Offline TwoTired

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Re: Petcock issues
« Reply #12 on: March 19, 2011, 04:39:27 PM »
Only three options I can thing of. 
Get a metric size pipe.
Drill to get yours a press fit.
Replace the fuel cock.
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Lloyd... (SOHC4 #11 Original Mail List)
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Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline socalenduro

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Re: Petcock issues
« Reply #13 on: March 20, 2011, 11:13:01 AM »
ok with LOTS of heat and some drilling of the petcock and sanding of the brass pipe its in there pretty good...
now i need to cut it to length
how long is the pipe supposed to be?
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Offline TwoTired

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Re: Petcock issues
« Reply #14 on: March 20, 2011, 12:02:58 PM »
The exposed length is 2.5 inches.
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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.
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