The infamous KDX petcock

[SS109]

As we all know the KDX petcock has a pressed in fitting for fuel line connection. After some time these can work their way loose causing leaks or coming completely out and dumping fuel all over your bike and you. Normally you can press them back in using some channel locks or similar and be fine. However, there comes a point where pressing it back in no longer works. I'm at that point now.

Mine popped completely out a few months back on the trail. I didn't notice until my bike died from lack of fuel in the carb. My engine and my boot was covered in fuel. Luckily nothing sparked so I'm alive to talk about it. Pressed it back in with some mini vise-grips I carry in my hydration pack but it still felt loose. I used a ziptie wrapped around the front and around the fuel line fitting on the back and that got me through the ride.

When I got home I drained all my fuel and proceeded to remove the petcock and give it a thorough cleaning and to get it pressed in really good. This Sunday I was about 15 miles in to my ride and it happened again. Thankfully a ziptie saved the day again.

My question is, if you have had this problem, what did you do to remedy it? Finding another KDX petcock is rather difficult and you still might have the same issue down the road. Finding a petcock from another bike would seem possible but what will bolt to the KDX tank and hopefully have a fuel reserve? Lastly, what could be done to the stock petcock to eliminate this problem for good? Could you get away with using green loctite? Maybe some of the thinner consistency JB Weld on the fitting when pressing it back in? Any other ideas?

[KDXGarage]

After carefully analyzing your situation, it has become clear to me that the answer is...TWO ZIP TIES!

[bufftester]

You can still get OEM petcocks, tho not cheap (~$70), and IIRC the KLX300 (the old one, not the new one) tap fits, but its even more pricey lol.
If you're feeling lucky (you feelin lucky, huh?) there's always this to try. It's only 12$, almost as cheap as those 2 zip ties
Then there's this one, a little bit more but comes with a 3 month warranty!

[Tyl3r]

I have newer WR250 petcocks on both of my KDX's. I like them because they seem to seal better and dont hang down as low. I cant recall the year range for it, i got the idea from this forum tho, maybe try doing a search on here.

[SS109]

After carefully analyzing your situation, it has become clear to me that the answer is...TWO ZIP TIES!

Well, I should have just kept the one on to begin with! Sadly, even with the ziptie, it seems to still weep.

Seems no one has ever devised a fix for the poorly designed petcock. I will be trying something and I'll report back what I tried and if it works or not.

[SS109]

You can still get OEM petcocks, tho not cheap (~$70), and IIRC the KLX300 (the old one, not the new one) tap fits, but its even more pricey lol.
If you're feeling lucky (you feelin lucky, huh?) there's always this to try. It's only 12$, almost as cheap as those 2 zip ties
Then there's this one, a little bit more but comes with a 3 month warranty!

Wow, that one is really cheap. I think I trust my worn out one more! LOL

[SS109]

I have newer WR250 petcocks on both of my KDX's. I like them because they seem to seal better and dont hang down as low. I cant recall the year range for it, i got the idea from this forum tho, maybe try doing a search on here.

I'll have to search for that. I knew someone swapped from another bike before but couldn't remember from what.

Man, we really need a multi-quote option on the forum.

[Tyl3r]

I have newer WR250 petcocks on both of my KDX's. I like them because they seem to seal better and dont hang down as low. I cant recall the year range for it, i got the idea from this forum tho, maybe try doing a search on here.

I'll have to search for that. I knew someone swapped from another bike before but couldn't remember from what.

Man, we really need a multi-quote option on the forum.

Just quote someone, copy all the text, then hit quote on another post. Then just paste in the text from the first quote. Then u can put multiple quotes in a message

Also, i think this is the one i used:

https://www.partzilla.com/product/yamah ... OwQAvD_BwE

[pumpguy]

This happened to mine some years ago, and I replaced it with the short one on eBay for like $12.00 or so.

I had considered using Loctite to bond the loose sleeve into the petcock's body. Loctite makes their wicking grade 290 which is for assembled threaded fasteners, and also recommended for sealing porosity in castings and welded assemblies. Seems to me this would be a good fix for this KDX petcock problem, but I never tried it.

[Molly's 70]

I would clean it up real good & JB weld it. I'm a welder by trade & I rarely use JB Weld, but this is a perfect use for it.

[SS109]

Just quote someone, copy all the text, then hit quote on another post. Then just paste in the text from the first quote. Then u can put multiple quotes in a message

Also, i think this is the one i used:

https://www.partzilla.com/product/yamah ... OwQAvD_BwE

Nah, that's just too much work with all that copy and pasting. Actually, I've done that many times but I was too lazy yesterday. Thanks for the link.

I had considered using Loctite to bond the loose sleeve into the petcock's body. Loctite makes their wicking grade 290 which is for assembled threaded fasteners, and also recommended for sealing porosity in castings and welded assemblies. Seems to me this would be a good fix for this KDX petcock problem, but I never tried it.

I would clean it up real good & JB weld it. I'm a welder by trade & I rarely use JB Weld, but this is a perfect use for it.

I just don't know how fuel resistant the 290 would be. I did find that Seal-All is supposed to be really fuel resistant and I've seen JB Weld used for decades inside wet intake manifolds and even cylinder heads. I'm going to try something that's for sure! I'll still pick up a new petcock just to have a backup.

[rungrandpa]

I used Seal All and it worked good fixing a leak in gas tank.

[doakley]

$51 at RMATV. I bought one this spring after my 21 yr old one did exactly as yours in an enduro. Not cheap but better than catching me and my bike on fire!

[pumpguy]

Just quote someone, copy all the text, then hit quote on another post. Then just paste in the text from the first quote. Then u can put multiple quotes in a message

Also, i think this is the one i used:

https://www.partzilla.com/product/yamah ... OwQAvD_BwE

Nah, that's just too much work with all that copy and pasting. Actually, I've done that many times but I was too lazy yesterday. Thanks for the link.

I had considered using Loctite to bond the loose sleeve into the petcock's body. Loctite makes their wicking grade 290 which is for assembled threaded fasteners, and also recommended for sealing porosity in castings and welded assemblies. Seems to me this would be a good fix for this KDX petcock problem, but I never tried it.

I would clean it up real good & JB weld it. I'm a welder by trade & I rarely use JB Weld, but this is a perfect use for it.

I just don't know how fuel resistant the 290 would be. I did find that Seal-All is supposed to be really fuel resistant and I've seen JB Weld used for decades inside wet intake manifolds and even cylinder heads. I'm going to try something that's for sure! I'll still pick up a new petcock just to have a backup.

To satisfy my curiosity and reassure others about the use of Loctite 290 thread locker and sealant for this KDX petcock problem, I gave Loctite's tech support a call to describe the problem and get their recommendation.

The reply I got was that Loctite has a manufacturer customer that uses their #290 on assembled screws inside a carburetor. Tech support went on to say that any of their aerobic products will work just fine in the presence of gasoline or other petroleum products. Obviously, surfaces need to be clean prior to application. I typically use acetone as a cleaner and surface prep when using Loctite products.

My thought about using this particular grade of Loctite is that it is a wicking type product. It moves by capillary action into the space between the bore of the petcock's body and the OD of the elbow insert. Kind of like the way solder flows when you're sweat soldering a copper elbow to a copper tube.

I have Loctite's current TDS for their 290 grade. If anyone would like to see it, PM me and I will send you a copy.

Hope this post is helpful to others.

[SS109]

Thanks for going the extra mile with the additional and very relevant info. I might just try it first since it will be the easiest to remove if for some reason it fails. Of course, it never hurts to have some 290 around and I've been out of it for a while now.

[Tyl3r]

Henkel makes glues to secure threaded fasteners and glues to help hold press fits, I would use something specfically for that type of fit if you're trying to do a repair. You could spend $30-40 on a glue to use a couple drops to hopefully work, or spend $20-30 for a brand new OEM petcock that you know will work. Just a thought.

[KDXGarage]

Thank you, pump guy!!

[pumpguy]

Henkel makes glues to secure threaded fasteners and glues to help hold press fits, I would use something specfically for that type of fit if you're trying to do a repair. You could spend $30-40 on a glue to use a couple drops to hopefully work, or spend $20-30 for a brand new OEM petcock that you know will work. Just a thought.

I would assume the OEM petcock would still be subject to the failure that is the subject of this thread. Maybe a different solution would be a better choice.

[Julien D]

Mine has had a zip tie around it for years, lol.

[SS109]

Henkel makes glues to secure threaded fasteners and glues to help hold press fits, I would use something specfically for that type of fit if you're trying to do a repair. You could spend $30-40 on a glue to use a couple drops to hopefully work, or spend $20-30 for a brand new OEM petcock that you know will work. Just a thought.

Excellent point.

I would assume the OEM petcock would still be subject to the failure that is the subject of this thread. Maybe a different solution would be a better choice.

Yeah, maybe the WR petcock, or one of the others mentioned, would actually be a better solution than trying to repair the OEM one.

Mine has had a zip tie around it for years, lol.

LOL! Good to know I'm not the only one that's done it!