Petcock nightmare pics

Hey everyone,
Well after a whole day of BS- I got the petcock rebuilt. I ran into more than a few snags though, and since I had my camera handy thought I'd share the pain. Now I'm trying to post the pics....

Here is a screw that held the petcock to the tank. Both of them looked like this- chewed up so badly I had to use the dremel to rip a notch in it and use an oversized flathead to get it out!

 

But wait there's more!

Ya know, I had a hard time figuring out why that petcock leaked all over everywhere. Take one look and see if you can tell me- yes it came out just like this!


That's right, the top gasket was folded back on itself, and the whole dang thing was rotated about 45 degrees! It's a wonder it would even get enough fuel to run at all!

 

OK Last one-

There was also a slight leak at the tank to petcock O-ring before I rebuilt the petcock. And when I was finally able to back out the Dremel-modified screws, I found a weird white/pinkish powdery substance all over them. Was it tank sludge? Was it anti-seize compound? No boys and girls it was PAINT! Paint? What? Why?!



Because SOME PO had an IQ that matched his/her shoe size. Why would you paint a surface that would come into contact with fuel like that? Who cares, it'll be RED! And to answer your next question, YES there were bits of old paint stuck on the fuel filter.

 

I can only hope at this point that NO carb or electrical work was attempted. But then again- it's not starting. Cry for me. Then pray for me... Still hoping to be riding by 2007, John

 

Prayers you shall have Satyr, however, you demonstrate resourcefullness, ingenuity, and cleverness. I doubt highly the gremlins infesting the bike have a chance. 2007? I give it a month (high stakes, what have I to loose?). Your pain was over swiftly, you fixed the problem and you didn't have to break out the torch or chisel. Count your blessings, your still on easy street. I bet your just itching to get it on the road. Soon, at this rate, soon. Wishing you luck, though I don't think you need it, Robert.

 

Satyr, any chance you might have a step by step rebuild picture set that you could post? I'm in the process of rebuilding mine (I think we had the same PO when it comes to the screws) and just trying to get an idea of how it goes back together. I hate it when I unscrew things and parts go everywhere without warning. ;-) I got it back together, but now it leaks. Taking it back apart in the morning.

 

Thanks for the encouragement Robert, we'll see how it goes. I ran the battery down getting her only to sputter last nite- now I'm battery charger shopping.

As for the step by step pic request, Beardking- I thought about doing just that but once I got the tank off- I couldn't help but dive right in. Once I heard myself say "OH SH*T!" I grabbed the camera.

So- I dunno if it helps, (and my bike could well be standing in a puddle of gasoline right now!) but I think there are a couple of spots where the petcock could be leaking from. I'd really check the o-ring between the tank and the petcock. It REALLY doesn't look like the crappy K&L o-ring that came with my kit is wide enough to give a real good seal there. With a couple of layers of crappy Krylon in there too- there really isn't a good surface for the o-ring to seat, so that could be a leak source.

Also- the oring on the toggle itself could be leaky- so I'd check that too- and make sure that weird looking wavy "spring" washer thing got put back between the outer plate and the toggle.

If the petcock is leaking from the body of the petcock, you might have put it back together wrong. The only thing to keep you from doing that are the little plastic tabs that help you mount it with the correct orientation. I had to look mine over a few times to make sure I didn't accidentally put it together wrong. -J

 

OH! and if the screws that mount your petcock to your tank are as stripped-out as mine were, you might not be getting them tight enough to properly seal the oring between the petcock and the tank.

Throw those old stripped screws out and run up to Home Depot. I replaced mine with 6mm metric hex-head bolts with 12 mm length, and 6mm washers. Worked just fine, and my nut-driver had plenty of room in there to tighten them down. Total cost with Chicago tax $.99!- J

 

Satyr, I took your advice and replaced the screws with hex head screws from HD. Just over a buck, but tons o' piece of mind. ;-) Now if I could just figure out what size the screws are that hold on the petcock lever so I could replace those bungled b*stards, I'd be good to go.

I do have a question for you though. I took apart the petcock (seriously, did they have to name it that????) today to see if I could figure out what was causing the leak and I noticed a little hole that seems to be molded into the plastic piece that goes between the layers of the diaphram (?) and that was were the leak was coming from. I'm attaching a pic for all to review and was wondering if anyone can tell me if I have this installed correctly. Thanks.

 

Hey beardking-
I think you may have your answer right there. The vacuum "nipple" on your "petcock" (BWA-HAHAHAHA! I love this pseudo-sexual technical jargon!) might be rotated 180 degrees.

On my 550, my fuel and vaccum hooks up on the same side and the little hole (is that a "wee-p hole? HAHAHAHA) is also on that side.

I went ahead and took some pics for you- hopefully I can get them to upload- they didn't come out REAL good- because I had to manually focus and hold the camera with my right hand, while I held the drop light with the other- and then tried not to fall down since I was crouching....

 

Here is a pic of the underside of my 550's tank. As you can see. (barely) when the tank is inverted and placed on the bike, the vaccum and fuel hoses hook up on the side of the petcock that faces the rear. That little hole (whatever its for) also faces the rear.

 

OK here's one more that might show up a little better...



Hope that helps!

 

Interesting.....

On my 82 650 Maxim the vacuum barb points rearward, just like the fuel barb.

One of us is backwards. Since mine doesn't leak.........

 

MiCarl is correct.
The fuel barb and the vacuum barb both face rearward. Also, the little vent slot should be on the lever side, pointing rearward.

Although personally, I've had enough of these vacuum petcocks. Tried rebuilding and tweaking my original several times. When that didn't work I set out on a www quest to find a NOS petcock, and got lucky enough to find one. (Current orders for a new petcock from Yamaha are on "back-order", which means we may never see new ones again.) I mounted the brand new petcock and guess what - it leaks! <sigh> Getting ready to order an ON/OFF replacement petcock as I write this.

Z

 

Hey, I had the same problem with my petcock, gas was leaking from the little hole, and mine is lined up correctly!
And considering the rebuild kit is 20 bucks, plus I don't know if that would even fix that little hole leak, I decided to do some looking up and replace with a ON/OFF/RES one.

This is what I just recently ordered from z1enterprises.com:

Petcock Adapter Plate 34mm 3/8 NPT

Petcock Custom Chrome Single Outlet 3/8 NPT

And all of this was $27.08, only $7 more than the petcock repair kit, and apparently the new petcock has no seals to worry about leaking

 

Hey Tichuang-
My rebuild kit was $43 with shipping! So if your adapted $27 petcock works out- you HAVE to let us all know about it! It looks like it would have been alot easier to install, and likely more reliable than any of these crappy rebuild kits we're all dealing with!

LET US KNOW HOW IT WORKS OUT FOR YOU!!!
-J

 

tichuang, why the heck couldn't you have posted that about 2 weeks ago? I would have gone that route instead. Dang it.

 

hey guys, i feel your pain, theres been tons of times I've ordered something only to find something better later on!

My parts come in today and I will be installing them tomorrow, so I will definitely let you guys know, with pictures too

-Tim

 

Hey, got the parts.

This is the new petcock screwed into the adapter plate.

It looks like I will have to enlarge the hole for the fuel screen, since it is cylindrical. The screen is brass, however, not plastic like in the OEM one, so it seems much more sturdy. Also there are no seals in this valve and compared to the stock one, it feels like a heavy, sturdy, and definitly shiny piece.




I imagine shaving out the hole would get metal shavings into the tank, but it shoudlnt be too bad sloshing gas around to get out most of it, and the screen/fuel filter will catch the rest. I'll post pics of the installation tomorrow.

 

Hey, anyone know what size adapter plate is needed on a XJ750J tank? This z1 petcock/adapter plate seems like the hot ticket!

 

it should be 34 mm, the one i posted earlier. someone else with an xj750 siad 34mm would be the right size as well

just to be sure, take a ruler and check the distance between the centers of the screws, i could eyeball it with the petcock and gas tank on the bike

 

Dang man, if I end up buying that thing for mine, I'm going have to buy all new bolts to attach it to the tank. I could only get the black steel bolts, and they just wouldn't look right at all on that thing. Looking forward to your evaluation of the new fuel tap.

 

http://xjbikes.com/Forums/viewtopic/t=2591.html

I posted up a writeup for installing my petcock, enjoy!

 

and it works great.