Uggghhhh... bad petcock

[adouglas]

I just pulled my gas tank off for the first time.

I've got a bad petcock... stuck open. It is DEFINITELY in the ON position and NOT the PRI position.

I didn't have the tank completely empty, so I got fuel all over the place. Probably spilled at least a pint, maybe much more, before I got everything under control.

Yuck.

I suspected something might be wrong last fall, when I tried to drain the carbs and kept on getting fuel flow.

So the only thing keeping the engine from flooding is the float valve seats in the carbs.....



I'm tempted to just buy the whole assembly (you can order it that way), but I took the vacuum side off (easy... five screws) to see what's going on in there.

This looks like an easy fix, even though I can't see anything wrong with it. I figure I just have to replace all the rubber parts, because that's about all that can go wrong with the thing.

Anyone ever rebuild one of these?

[adouglas]

Ah, heck.

You can't buy the diaphragm part without buying the whole flippin' thing.

[kkim]

Is it possible to make your own using a piece of rubber and the old diaphragm as a pattern?

[petiteninja]

i think my ninja had the same problemo, the gas gauge wasn't working at all...are you still under warranty? they replaced the float valve and seems to be working fine now.

[adouglas]

Uh... this has nothing to do with the fuel sender.

It's the petcock... the fuel valve.

I doubt I could fabricate my own part. I've never seen rubber this thin in my life. Maybe in a latex glove, but this isn't latex. And the shape must be precise.

Besides, it might not be the diaphragm at all. It might be the O-ring that seals the fuel line, which is also unusual.

I'm assuming it's the diaphragm because it's obviously very delicate.

[kkim]

http://motors.shop.ebay.com/__?_from...etcock&_sacat=

[coolbreeze]

Originally Posted by kkim

http://motors.shop.ebay.com/__?_from...etcock&_sacat=

Mine is a 2000, but I got my petcock and carbs from ebay. I think I paid ~$60 total.

[Racer x]

I almost blew up my garage . I took off an new ninja gas tank and set it on my work bench. There was a space heater cooking away on the other side . When I left and came back the top of the workbench was covered in gasoline!!!!!

I cleared and ventilated the building after cutting the power .

I tried to repair the petcock .You can order the disc but not the diaphragm. I tryed to repair the petcock but the metal side of the seal was pitted.

[g21-30]

I just found a company on the 'net last week that specializes in diaphragm replacement, but can't remember the name. For our ninjas, it would have been $175 for 2 carb ones!

[adouglas]

On closer inspection I found the problem. The diaphragm is fine.

Inside the petcock is a small metal piston with an O-ring around the end of it. The piston is mounted in the center of the rubber diaphragm. The end of this piston is held against a circular opening inside the petcock by a spring. Fuel flows through this opening, from the tank to the engine.

When engine vacuum is applied, the piston is pulled away from the opening and fuel flows. When the vacuum goes away, the spring pushes the piston back into place and the flow stops.

Here's the defect:

At the base of the opening is a ring of white packing material that looks like teflon. This is what the end of the piston seals against.

On mine, this white ring is defective, preventing the piston from seating.

This is not a replaceable or repairable part. You need to replace the entire petcock.

[coolbreeze]

Well, if the '09 is the same as '08, there's one one ebay for less than $25 (buy now + shipping).

[adouglas]

Replaced the petcock today, so here are some pics to show what I'm talking about.

[kkim]

Thanks for the pictures, Andrew.

[komohana]

how much did that cost ya?

[adouglas]

$70 or so.

I decided not to go with a used one because of the delicacy of the rubber bits inside it. I've never seen butyl rubber that thin.

The bike actually worked just fine... the carb bowls were kept from overflowing by the float valves. But if one of those were to go bad, it'd be messy at best and very dangerous at worst.

I can't for the life of me think of a good reason for Kawasaki to use this kind of petcock. Give me a good, old-fashioned, PROVEN manual spigot any day.

[Flow]

You know you really need sleep when you read the entire first post without realizing Andrew wasn't talking about being a sadist/dom.

You also realize you know as much about mechanics as a mid-1940s housewife.

[adouglas]

Uhhhhh... heh heh... he said "petcock."

[Flow]

Not just that, but I'd rather not get too off-topic. Hope your used petwilly treats you well.

[randomwalk101]

$70? Whoa you can pick a used one off eBay for around $15.
I bought an extra one back then when I had some fuel issues.
Posted via Mobile Device

[komohana]

Originally Posted by adouglas

$70 or so.

I decided not to go with a used one because of the delicacy of the rubber bits inside it. I've never seen butyl rubber that thin.

yeah good call there andrew. worth the price.

Originally Posted by adouglas

The bike actually worked just fine... the carb bowls were kept from overflowing by the float valves. But if one of those were to go bad, it'd be messy at best and very dangerous at worst.

THAT kind of fire we DON'T need tween our legs
better off fix'n it now for sure

[CZroe]

Originally Posted by adouglas

Replaced the petcock today, so here are some pics to show what I'm talking about.

This keeps coming up and not nearly enough people know about this. It should come up in every "common problems to look for?" or "known defects?" discussion. @Alex: PDF requested!

[CZroe]

After Danny (sLick415) reported that taking his petcock apart and putting it back together solved his problem, I decided to do the same with mine. I took a look and saw something seemingly quite different from Andrew's problem though the defect is likely the same.

Like Andrew's defective petcock, the ring inside is not round. The major difference is that, instead of an incomplete ring, mine had what seemed like excess material blocking the opening and stains where the gas had been leaking out. When looked at from above, you can see some of the material forming a film slightly covering one side of the opening such that the ring is not round. The edge of the film is jagged.

In case this excess material was blocking the center pin from seating fully and causing my petcock to leak, I decided to see if I could correct it by removing the excess film. Sure enough, it fell right off by simply touching it with a pick. It turns out that wasn't the problem at all though.

The whole thing was pretty rough and dirty so I decided to clean up the rest of the petcock as best I could before putting it back together. I wanted to make sure that everything else would seal as well as possible, so I rinsed the rubber and other small parts and cleaned the exterior with 97% isopropyl alcohol and cotton swabs. When I was done, I decided to see if the interior stains inside would wipe right off, so I VERY delicately touched it with another wet cotton swab only to make another discovery: The "stains" were actually old gas trapped inside hollowed-out portions of the ring material which collapsed as soon as it was touched, now replicating the problem Andrew had exactly.

As it turns out, what looked like stains around the opening were gaps in the material with an extremely thin film over it. Touching it caused it to flake off completely. When reviewing my earlier pictures I can see what looks like a spiral of the material going even deeper into the petcock. It seems clear to me that this is the displaced material from a bubble in the mold when the ring material was still liquid.

I do wonder just how many petcocks are like this because many people never know theirs even leaks and most who do just replace it (very few people investigate). It may be something Kawasaki and Taiyo Giken have already identified and addressed with later production years using an extra QA check or with steps to prevent bubble formation or whatever causes this, but I do see plenty of 2011/2012 "leaky petcock" threads. If the EX250L/EX300A/B use a similar petcock and the problem has not been fixed, we need enough new owners to check and discover it within warranty for Kawasaki to take notice.

@Alex @choneofakind

[Alex]

Why do you keep mentioning me?

[CZroe]

Originally Posted by Alex

Why do you keep mentioning me?

Originally Posted by CZroe

@Alex: PDF requested!

To get it archived as a PDF attachment before his image host changes or we lose it some other way.

[Alex]

PDF added to that post.

[choneofakind]

Interesting find.

You might want to try some of that gas tank epoxy. Glob it in there, then take some time with a file to get a smooth surface for your o-ring to seal on.

[CZroe]

Originally Posted by Alex

PDF added to that post.

Thank you much.

Originally Posted by choneofakind

Interesting find.

You might want to try some of that gas tank epoxy. Glob it in there, then take some time with a file to get a smooth surface for your o-ring to seal on.

No reason not to try on the bad one once I get a replacement. I could use the old O-ring/pin ("piston") to form it while it's still malleable because that is a replaceable part.

Both rubber films were practically glued to the surfaces they contact and went through a lot of stress when I took it apart so I am still going to replace it for peace of mind and then I can play with this one without worry. The surface still looks gunky and might affect adhesion, so I may need to go ahead and remove the whole ring and clean it rigorously, which I can't do now because it's my only petcock (much bigger leak if the rest of the ring flakes off).

Edit: Perhaps this stuff will do the trick.

[sLick415]

To my surprise, mine was quite clean and all the rubbers still looked fresh. The only thing i had to do was stretch out the spring and manipulate the wavy washer lookin thing to give it the gasket a better seal.

[CZroe]

Originally Posted by sLick415

To my surprise, mine was quite clean and all the rubbers still looked fresh. The only thing i had to do was stretch out the spring and manipulate the wavy washer lookin thing to give it the diaphragm a better seal.

"Wavy washer?" Is that the plate-like backing thing the spring pushes on?

[sLick415]

Originally Posted by CZroe

"Wavy washer?" Is that the plate-like backing thing the spring pushes on?

Its right behind the face plate. I guess its more of a ring than a washer.

[CZroe]

Originally Posted by sLick415

Its right behind the face plate. I guess its more of a ring than a washer.

The face plate with the "On" and "Prime" markings? I don't recall the ring under mine being wavy, so I wonder if yours might be revised. Despite the parts diagram showing more, I couldn't get it apart any more from that side and I didn't want to pry, especially after seeing what I needed to see from the other side.

[sLick415]

Originally Posted by CZroe

The face plate with the "On" and "Prime" markings? I don't recall the ring under mine being wavy, so I wonder if yours might be revised. Despite the parts diagram showing more, I couldn't get it apart any more from that side and I didn't want to pry, especially after seeing what I needed to see from the other side.

It most definitely is supposed to be wavy. Dont be afraid to pry out the valve to inspect the gasket. Its not attached to anything. It just sits on the gasket.

Edit: Just found out theyre called spring washers.

[2WheelGuy]

The petcock off my '08 has been leaking. I ordered one off Ebay from an '12 model. It leaks too. I took them apart and they look fine. I stretched the spring a bit and put them back together. So far no leaks.

[CZroe]

Well, guys, I waited for a good deal on one and finally bought a brand new petcock with "10/2011" on the label (made for 2012 bike?). The seller originally got it from Ron Ayers and never opened the bag or box. Anyway, I was extremely curious to know if it had the defect so I unboxed it and took it apart on camera.

I'm glad I did, because the fuel filter was already broken, which seems to have happened under its own weight while shipping (nothing to protect it in the box). The Teflon-like ring was either revised away by the time this one was made or it's defective in the sense that it's completely missing. Either way, I think it's confirmation that there were problems with the older part. Why would they change something that wasn't a problem?

I haven't checked to see if the part number ever updated but this could be a revision made without Kawasaki's knowledge or input from the fuel tap manufacturer.

Edit: I see I suggested that long ago.

Originally Posted by CZroe

It may be something Kawasaki and Taiyo Giken have already identified and addressed with later production years using an extra QA check or with steps to prevent bubble formation or whatever causes this, but I do see plenty of 2011/2012 "leaky petcock" threads.

Anyway, does anyone have any idea how to replace the fuel filter piece?

[cbinker]

I hope you punished that bad petcock.

[CZroe]

Originally Posted by cbinker

I hope you punished that bad petcock.

Originally Posted by adouglas

Uhhhhh... heh heh... he said "petcock."

[maverick9611]

mine leaks too(2008 model)
what about the rebuild kit they sell on ebay?

[Ram Jet]

Originally Posted by Alex

Why do you keep mentioning me?

Because they think your helmet is WAAAAY too big for your head.

Bill

[Bluberryrain]

Too late now, but here's this:

http://www.ebay.com/itm/Fuel-Petcock...BX2q1G&vxp=mtr

[maverick9611]

Originally Posted by Bluberryrain

Too late now, but here's this:

http://www.ebay.com/itm/Fuel-Petcock...BX2q1G&vxp=mtr

their is tons of rebuild kits for this defective part.. this thread at beginning said it was couldn't be rebuilt. just trying to clarify.