Petcockrepair

Had a leaking petcock (when I took of the fuel hose it dripped). The
dripping stopped when I blew in the vacuumhose which led me to believe it
was the spring. Instead of stretching it (I was afraid it would just be to
loose again) I found one of those combined nut/washers that fitted the
spring and also - with a little filing - the springseat in the petcock (I
checked with the spring compressed that there would be space enough for the
nut/washer and the metal pushplate behind the diaphragm).

And the bike is running fine.. (apart from some idleproblems, but they have
been there for some time..)

A side note is that when removing the fuelhose, I noticed the gasoline
stayed in the hose - so I guess my floats are working ok.

and finally - got a spare petcock from a friend. the diapragms were
impossible to remove without damaging them but having found a UK source for
the Kawasaki kit, I took them apart - and found out his o-ring was different
than mine (more "normal" and stiffer, whereas mine was softer with another
shape (don´t know the english word for it)). I switched to his o-ring and
thus can´t tell if the o-ring was the problem - main thing is the bike is
running ok.

I´ve put up some pics in a small homepage under "fotoalbum":
http://www.maximdk.k-nettet.dk/main/pho ... ?wid=18222

Finn, XJ700N, Denmark

 

At last !!!! Photos of the petcock oring! Conical is the english word you didn't know for the shape. Thanks so much for posting those pics. Now you need to put them up on this site so we hav ethem for future reference. Anychance you measured the oring's diameter and wall thickness? This would help me in finding the replacement oring and posting the info for everybody.

 

I believe the pic of the old one was at one time an oring. It has just taken the shape of the seat over time.
With the oring shaping itself that way the stem has become shorter sinking further into the seat, moving further away from an already weaker spring due to age, heat etc.. No wonder it leaked.
Glad to hear you got it fixed.


Just my $.02

 

Ok. Didn't realixe an oring would change that much. But that's even better. ONce we have the right dimensions we can order what we need from McMaster-Carr.

 

Hi guys

No, sorry; didn´t measure the o-ring. Thought about, however, just before falling asleep, that one possible downside on my nut-washer solution is that I´m expanding the lenght of the fully compressed spring (with the thickness of the washer (1-2mm)) - thus maybe preventing diaphragm/metaltap/o-ring from fully opening from the conical area..

Maybe I can check with my spare if it is an issue to worry about. If so, I might (might do that anyway) try and remove the nut/washer and see if the "new" o-ring will do the trick by itself. Seeing the fuel didn´t disappear from the fuelhose when disconnecting it from the petcock I´m not so worried anymore..

The "old" o-ring (the conical one) was way softer (almost sticky) and far easier to remove than the "new" one I switched over to

I´m having some idle problems after a mechanic´s carb sync, so I can´t really tell if my repair is having a bad effect on low-rpm - could also be dirt in carbs, don´t know (also my choker is behaving oddly - when I pulll it, the engine dies, regardless of being hot or cold (did this before the repair as well)).

Anyway o-ring pic coming up:

 

This link is no longer working, pics can be found here:

http://hjem.get2net.dk/xjmaximdk/vedlrep.htm#Benzinhane

 

In another post I reported on using a Kawasaki diaphragm part #43028-1021 ( info obtained from the XJCD ).

I went to the local Kawasaki dealer, found out the price $17.63 cdn, ordered it on a Saturday and received it the following Tuesday.

Here's a pic....

 

Hi Nick

Thanks for the pic - looks like the Kawasaki kit has a "normally" shaped, roundish o-ring (which I believe must make a better shut-off than the conically shaped..)

 

Finn, I think the "round" o-ring will go conical after some use and time!

 

You could be right, Nick, but the "good" o-ring, I replaced mine with had been on a bike for 10-15 years (petcock was only replaced due to a leaky tank, replaced with one with another (also working) petcock installed..

Do you know for sure that your original petcock is "original"?

Anyway - if the o-ring could be the main cause of leaking, I think that would be good news (replacement o-rings must be trackable..)

I´ve bought a SH XJ900 Petcock from Ebay and will be disassembling it soon - also this winter will be disassembling the one I´m using now and try to run it without the extra pressure on the spring - just to check if the o-ring alone was causing the leak..

Can´t be right that such tiny items can cause such big problems... :evil:

 

I can only assume that the petcock is the original. I've had no contact with the previous owners, so don't have any history on the bike.

The o-ring is the main shut off seal for this valve, and the spring tension is what pushes it closed.
You would think that an o-ring could be found someplace, but must be fuel grade material.
You're right, it usually is some dumb little part that causes most of the grief!