Author Topic: Intermittent Leaky Petcock?  (Read 14003 times)

Offline wyowanderer

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Intermittent Leaky Petcock?
« on: May 14, 2011, 07:44:22 PM »
On a recent road trip I found my manual petcock (Bergmen conversion)to fail intermittently.  I proved this by turning it off and on while riding.  At times the carbs were still getting fuel when in the off position.  Other times it worked as intended.  I ordered a rebuild kit thru Murph the other day.  Have others had this occur?

2002 Concours
COG #9461

Offline T Cro ®

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Re: Intermittent Leaky Petcock?
« Reply #1 on: May 14, 2011, 08:11:10 PM »
Have not heard or had this happen as I've had Bergmen's conversion almost since he introduced it 7 or 8 years ago.

How long were you turning it off for while you were riding?
Tony P. Crochet
(SOLD) 01 Concours Winner of COG Most Modified in 2010

Offline Nosmo

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Re: Intermittent Leaky Petcock?
« Reply #2 on: May 14, 2011, 11:47:07 PM »
I also have had Bergmen's manual conversion for several years and had the petcock leak some time ago.  Dan's kit just repositions the innards and replaces the handle, but does not affect the internal seals.  The problem I had was the O-ring that seals the poppet spindle of the vacuum valve had worn out.  If that O-ring leaks, then you will have fuel seeping through the petcock even when "OFF". I also had a problem with the K&N repair kit, as the poppet valve spindle was too small diameter and so was the O-ring for it.  Instead of sealing the internal orifice, it just let fuel flow past it.  I had a spare new valve assembly and installed that.  Make sure your repair kit has the right sized parts and TEST it for leakage before installing it.
A life undreamed is a waste.  A dream unlived is a sin.

Offline wyowanderer

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Re: Intermittent Leaky Petcock?
« Reply #3 on: May 15, 2011, 05:05:43 AM »
T-Cro...at one point I had it turned to off and rode for 1/2 hour at interstate speeds!  Later in day while still on my trip I would fiddle with it some more and it would work as intended.  Nosmo, I hope my K&L rebuild takes care of the issue.  I was contemplating getting the OEM petcock, but opted for the cheaper of the two solutions. 
2002 Concours
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Offline T Cro ®

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Re: Intermittent Leaky Petcock?
« Reply #4 on: May 15, 2011, 08:03:30 AM »
Yikes that's a long time... It is leaking by no question there! Good luck with the K&L kit as I've heard lots of disapointing reports on their quality.
Tony P. Crochet
(SOLD) 01 Concours Winner of COG Most Modified in 2010

Offline MAN OF BLUES

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Re: Intermittent Leaky Petcock?
« Reply #5 on: May 15, 2011, 11:50:59 AM »
I have never been pleased with the K&L petcock diaphragm assembly, and quite frankly it dissapoints me. This is about the only part on the bike I recommend the OEM part (diaphragm only, not the complet petcock) as it seems to be wayyyyyy more reliable. And I've repaired a lot of these valves.

46 YEARS OF KAW.....  47 years of DEVO..

Offline wyowanderer

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Re: Intermittent Leaky Petcock?
« Reply #6 on: May 20, 2011, 06:41:00 AM »
Not what I wanted to hear MOB.  Gonna attempt the rebuild kit today after work.  Any words of advice from other Coggers?  I see on Murph's site he recommends removing any nicks or burrs upon reassembly, stretch spring a bit, clean everything up real good, and not to over tighten anything. 
2002 Concours
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Offline T Cro ®

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Re: Intermittent Leaky Petcock?
« Reply #7 on: May 20, 2011, 06:51:22 AM »
Not what I wanted to hear MOB.  Gonna attempt the rebuild kit today after work.  Any words of advice from other Coggers?  I see on Murph's site he recommends removing any nicks or burrs upon reassembly, stretch spring a bit, clean everything up real good, and not to over tighten anything.

Use a little grease to lube the parts and o-rings before putting back together........
Tony P. Crochet
(SOLD) 01 Concours Winner of COG Most Modified in 2010

Offline wyowanderer

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Re: Intermittent Leaky Petcock?
« Reply #8 on: May 20, 2011, 05:47:19 PM »
Well, I have about had it!  Took my time putting the K&L kit in following some detailed well written instructions from a past 2009 Concourier article.  It leaks worse now than it did before!!  I am assuming I put it back together correctly.  If I screwed anything up it was putting the diaphragm in.  But it appears to only go in one way.  Can't say I am real impressed with the diaphragm in the kit.  Seems cheesy.  Maybe this is the problem???  Guess I should have just bit the bullet and got the OEM petcock in the first place.

2002 Concours
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Offline Uded2me

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This forum is dead dead dead
« Reply #9 on: May 20, 2011, 06:32:11 PM »
d e a d
« Last Edit: February 21, 2016, 09:06:01 PM by knight_mare »

Offline MAN OF BLUES

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Re: Intermittent Leaky Petcock?
« Reply #10 on: May 20, 2011, 09:36:02 PM »
Not what I wanted to hear MOB.  Gonna attempt the rebuild kit today after work.  Any words of advice from other Coggers?  I see on Murph's site he recommends removing any nicks or burrs upon reassembly, stretch spring a bit, clean everything up real good, and not to over tighten anything.
Sorry, but since you ain't paying me, or laying on my couch, I ain't tossing a box of tissues at ya....
I tell it like it is, that's all....everyone's an expert, just depends on the level.
With that said, you CAN make every effort to get the K&L to work, that entails stretching the spring about 1/4", polishing the back side plate on a piece of wet/dry 400 grit paper on a piece of glass, cleaning the surfaces, noting which way the vent on the backplate goes.....installing the diaphragm correctly, and crossing your fingers.

Murph DOES sell the OEM diaphragms also, I am sure he does, he sells Kaw parts... I wouldnot order a whole damned petcock, I have had great luck with the OEM diaphragms. Just saying....

P.S.
I'm gonna have a talk with Gary about those K&L diaphragms again, I have told him a couple times about the issues, I think he'll get all cool and dump them if I tell him nicely how crappy they really are.... OEM is the best, the only OEM part I insist upon on the whole damned bike.
well, clutch friction plates...but that's another story////

46 YEARS OF KAW.....  47 years of DEVO..

Offline wyowanderer

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Re: Intermittent Leaky Petcock?
« Reply #11 on: May 21, 2011, 05:17:28 AM »
Well if anyone is going to install things incorrectly it would be me, so I am not ruling that out by any means.  MOB, I did use the fine sandpaper on the mating surfaces and stretched my spring a bit as well.  Take a look at my photos I attached.  I hope someone out there tells me I installed it wrong! 

1st photo:  Does plastic disk go down first with it oriented like I have it?  Is the weephole in the right location on plastic disc?  Does diaphragm get placed into plastic disc like I am doing?

 2nd photo:  Does spring get placed on diaphragm like I am doing and then outer cover ontop of spring?
2002 Concours
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Offline Mettler1

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Re: Intermittent Leaky Petcock?
« Reply #12 on: May 21, 2011, 06:56:34 AM »

   Judging from the pics this man is not a gearhead. No dirty,greasy fingers and manicured nails??? ;D ;D
'94 Concours 112,000 miles-- 7th gear,2MM,KB fork brace,Over flowtubes,Stick coils,Tcro shifter,GPS,Torque cams,SPOOKFAK,block off plates, SS brake & clutch lines,KB risers, FENDA EXTENDA, emulators,etc

Offline Nosmo

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Re: Intermittent Leaky Petcock?
« Reply #13 on: May 21, 2011, 01:00:36 PM »
wyowanderer:

When mine leaked after installing the K&L kit, it was due to an undersized poppet valve and O-ring.  That's the part I have circled in yellow in your picture (copy attached below).  That O-ring must fit the center spindle tightly, and also must tightly seal against the central hole in the valve body.  Check the new unit against the old OEM assembly that you took out.  The diameters must be the same, and the O-ring cross-section must be the same.  Even a few thousandths of an inch can cause problems because the fuel is so thin it doesn't take much to let it past.  If that aluminum spindle or O-ring are not correct, then fuel will seep past it and leak out the outlet pipe all the time regardless of the petcock valve position, whether vacuum is applied or not.  Good luck.
A life undreamed is a waste.  A dream unlived is a sin.

Offline MAN OF BLUES

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Re: Intermittent Leaky Petcock?
« Reply #14 on: May 21, 2011, 01:06:06 PM »
DID YOU DISASSEMBLE THE DIAPHRAGM YOU GOT THAT WAS NEW?????

IT SHOULD DROP IN THERE......
THAT DOES NOT LOOK RIGHT...... ???

46 YEARS OF KAW.....  47 years of DEVO..

Offline wyowanderer

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Re: Intermittent Leaky Petcock?
« Reply #15 on: May 21, 2011, 01:29:36 PM »
MOB, Yes I did.  Even took photos...but the majority of photos were too blurry to see, hence this thread. Mechanics are not my strong point, but I do what I can.   I looked at a microfiche as well, but just got plain confused.  I am used to looking at past threads and using the search function to help me out, but with the site crashing and all...

Nosmo, I think you may be onto something.  It appears that poppet valve you circled IS smaller than the OEM one.  I suppose I would need a micrometer to verify this though.  But I am not banking on this yet.  I want to make sure I have installed the diaphragm correctly first. 

Thanks.
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Offline MAN OF BLUES

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Re: Intermittent Leaky Petcock?
« Reply #16 on: May 21, 2011, 01:30:27 PM »
DID YOU DISASSEMBLE THE DIAPHRAGM YOU GOT THAT WAS NEW?????

IT SHOULD DROP IN THERE......
THAT DOES NOT LOOK RIGHT...... ???

there are 2 diaphragms  attached to the poppet, one on either side of the plastic frame.....

I have no idea what you tried to do here....it needs both in tact, if you ripped one outta there it will never work, and it ruins the assembly.

the kaw assembly comes correctly with a new plastic frame in place....look closely, one diaphragm layer goes on either side of the frame, and the groove in the frame goes against the poppet side as the photo showed.
it will never work any other way, the rubber seals against each metal mating surface, thus the reason it's said to clean/true them and de-burr them.


46 YEARS OF KAW.....  47 years of DEVO..

Offline MAN OF BLUES

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Re: Intermittent Leaky Petcock?
« Reply #17 on: May 21, 2011, 01:56:24 PM »




like this.....


Nice try Nosmo.... but you looked right past the obvious....

 ;)

46 YEARS OF KAW.....  47 years of DEVO..

Offline MAN OF BLUES

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Re: Intermittent Leaky Petcock?
« Reply #18 on: May 21, 2011, 02:11:58 PM »
saving further time, I know you are gonna ask this also....
the back plate gets installed with the hose spigot alligned with the fuel spigot...both on the same side...... the weep hole inthe diaphragm plastic frame faces downwards, the plastic pins and holes in the rubbers, all allign this correctly, mind them meticulously.

carry on.

46 YEARS OF KAW.....  47 years of DEVO..

Offline wyowanderer

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Re: Intermittent Leaky Petcock?
« Reply #19 on: May 21, 2011, 03:03:18 PM »
Holy Cow!!!, Now I am thoroughly confused and miffed.  I DID NOT dismantle the diaphragm that was new.  (Nor the old one..the diaphragm that I took out was not sandwiched between the plastic frame).  The K&L kit does not come with that plastic frame so I am assuming I have to dismantle the new diaphragm to put it on the existing frame?  Can this even be done?  It looks to be a pressed item. 
2002 Concours
COG #9461