thoughts/ opinions requested on leaky tank petcock

[sbaugz]

So I finished my bike and ran into a problem. Its a 1981 xs650 special with a XS750 tank. The tank is coated with caswell. The tank has two petcocks. Instead of the stock, I decided to use pingel petcocks with adaptor plates. The painter got my tins back to me and I proceeded to install petcocks and ultimately I rode the bike for a few days. Unfortunately after two days I noticed one of the petcocks was leaking around where the adapter plate attached to tank itself. Even worse, the gas proceeded to track between the paint and the metal tank so I got an area about 3/8" beyond the adapter plate where the paint bubbled up. The painter has graciously agreed to fix it or even repaint the whole tank if needed. The problem arose from improper cleaning and/or masking around the plate mount area.

Anyways, I have been messing around with the plates, trying to get a good seal on them to the tank. I tried permatrex permashield which is supposed to be gas proof but that leaked immediately. I then sanded down the mounting area on tank as flat as possible and reinstalled the plates using the rubber gaskets that it came with again. This time is seems to be holding, but I am really nervous it will ruin the paint if it starts leaking again.

In retrospect, I should have welded plates onto tank, but I cannot do that now.
I was thinking of roughing up the surfaces of the plate and the tank and using some JB weld to permanently affix the plate to the tank. After that, I was thinking of recoating the entire tank inside with another thin later of caswell epoxy sealer to seal any small channels between plate/ tank/ JB weld. Do you think this is a bad idea? This would permanently affix that plate and I shouldn't have to ever worry about it again, maybe? The plate has a standard 3/8 NPT threaded hole for pingel petcock and I would leave those threads intact so I could still remove and rebuild the actual petcock if needed.

Thanks for advice
On attached pic below, you can see where the paint came off around plate.

 

[jd750ace]

I have excellent sealing results using Permatex Ultra Black. It works against all fluids. I wouldn't advise the JB.

 

[DogBunny]

JB Weld is wrong for this application, in my opinion. The gasket that was supplied with the petcock is correct in my opinion. No sealant of any kind should be used in my opinion. The sealing surfaces have to be smooth and clean for the supplied gasket to work. I guess they weren't initially, but now they are, the tank is not leaking, so I would stop worrying about it, and call it done.

 

[jd750ace]

People have had problems with Road Stars using the Pingel adapter plates as well, and have used the Ultra Black, and it works. Having said that, I have to agree with DogBunny though. If you have it working as advertised, I wouldn't add to it.

 

[xjwmx]

Personally, I wouldn't be able to leave well enough alone.

I'd take the painter up on his offer of patching the damage, and instead of repainting the tank I'd get him to give it a fuel proof clear coat. Definitely.

To seal it, if nothing good comes with the petcock, I'd use a piece of fiber gasket and coat both sides generously with Seals All. It appears to really stand up to fuel, as advertised. JB isn't advertised as fuel proof and if it was it would still be too permanent a kind of repair.

 

[sbaugz]

Personally, I wouldn't be able to leave well enough alone.

I'd take the painter up on his offer of patching the damage, and instead of repainting the tank I'd get him to give it a fuel proof clear coat. Definitely.

To seal it, if nothing good comes with the petcock, I'd use a piece of fiber gasket and coat both sides generously with Seals All. It appears to really stand up to fuel, as advertised. JB isn't advertised as fuel proof and if it was it would still be too permanent a kind of repair.

The painter already applied three coats of fuel proof paint but the gas seeped between the primer and the metal tank so the whole thing peeled off. No amount of Fuel proof paint will prevent that if the gas gets in between the metal and paint. I guess it was dumb luck that that happened. If the gas had leaked and travelled on outside of paint, it would have been fine.

I guess I was just looking for a way to prevent future damage. My luck, I would have painter fix it and then it would spring a leak and ruin paint down the road.

I realize JB weld is not Fuel proof which is why I was thinking of resealing inside with another layer of caswell after the JB weld has cured. After comments here, I won't do that now.

I think I will just roll with things for now as long as its not leaking. The painter said he would touch up or repaint entire tank this winter if I wanted, so maybe I will just see how things go and if it doesn't leak by September, then go ahead and send back to painter for repair. I have also heard of Dow Corning 730 sealer too. Supposedly fuel proof and designed for airplane fuel tanks and fuel pumps. Expensive at $90 a tube, but its worth it if it works.

Another thought I had was ditching the pingels and going back to stock xs650 petcocks from mikes but that may not work now because I had to make the hole bigger in the center of mounting area to accommodate the larger pingel fuel inlet

 

[jd750ace]

If you are ever looking for an aircraft grade fuel resistant sealer it can be had for way less than 90 bucks. AMS-S-8802 is used throughout the industry for sealing fuel tanks and pressurized structure. I've used many, many gallons of it over the years. This is the stuff 98% of aircraft fuel tanks are sealed with. 2 ounces is way more than enough. It stinks, and can be really messy, but it works. P.S., don't get any on ya! It's a bitch to get off with anything but M.E.K.

http://www.aircraftspruce.com/catalog/appages/prosealant.php?clickkey=4275

The Dow Corning products are good, but not worth the cash you are looking at.
$0.02

 

[TwoManyXS1Bs]

Ditto on the JB weld. Manipulating the petcock induces loads on the adapter plate, JB will eventually microcrack, you need something compliant, like the seal you have now and/or the aircraft sealer.

 

[sbaugz]

I think part of the issue is that the rubber gasket squishes out too much so maybe some sort of paper gasket would be better? If so, what kind should I look for?

 

[gggGary]

The painters seldom mask off the petcock area. I razor blade the paint off that area and mix a bit of clear epoxy to seal the paint/primer/metal edges. Just so no one thinks permatex yeah I got some of that. The standard ppermatex "aircraft gasket sealer is NOT fuel proof. it will migrate straight to your carbs. I just found this on a bike I got that had Pingles and the aluminum adapters. I removed them and put in stock vacuum petocks with all new seals and orings, no leaks. I may try JD's aircraft sealer some day but +1 welded on bungs are the best way to do it.

 

[sbaugz]

The painters seldom mask off the petcock area. I razor blade the paint off that area and mix a bit of clear epoxy to seal the paint/primer/metal edges. Just so no one thinks permatex yeah I got some of that. The standard ppermatex "aircraft gasket sealer is NOT fuel proof. it will migrate straight to your carbs. I just found this on a bike I got that had Pingles and the aluminum adapters. I removed them and put in stock vacuum petocks with all new seals and orings, no leaks. I may try JD's aircraft sealer some day but +1 welded on bungs are the best way to do it.

Gary
I would assume since you used the adapters and pingels that you had to enlarge the hole in the tank to the pingel to fit? I had to enlarge the holes a fair amount to accommodate the 3/8" pingels. i thought the easiest fix would be to use stock petcocks with o rings but I am worried that the hole is enlarged too much now in the center and the o rings would go right over the top of the enlarged hole

 

[TwoManyXS1Bs]

Take a look at nj's post #9:

http://www.xs650.com/forum/showthread.php?t=27162

 

[jd750ace]

Good info there on modding the hole. This is a quote from the Road Star Clinic discussing the Pingels, with a part number for the 1/4 inch version you can search for. They are out there.

Back in 2002, I added the pingel to my 01 bike for my S&S carb. I thought it was kind of stupid that you had to file the tank for the screen to go up into the tank. So I called Pingel and discussed it with them. They told me there was another petcock that would work.

According to Pingel, part number 4111-AH with adapter plate A1601C has a smaller tube and would not require filing the tank. The petcock is polished aluminum, not chrome brass but the adapter plate is chrome. The adapter plate is also a little thinner. They told me that even this petcock would flow more than our engines could ever use.

Just wanted to throw this out there as I see vendors still list the 3/8 version and the one I list has a 1/4" npt and screen. I see folks still filing the tank opening so check it out before you order to verify. This information is only to tell you there is an option if you decide you want a pingel petcock and nothing more.

http://www.pingelonline.com/powerflo_4111.htm

http://www.pingelonline.com/powerflo_adapter_plates.htm

This explains what the numbers represent in the part: http://pingelonline.com/powerflo_valve_positions.htm

[CLOSE QUOTE]

 

[sbaugz]

Wish I would have known about the 1/4" ones. I feel like I am beyond going back to the stock ones now since I enlarged those holes so much.

Does anyone have a crappy stock petcock that is junk that they wouldn't mind sending me to see if a stock one would still work on my setup?
I would pay you to have it sent to me and returned just so I could check.
I don't want to pay for a new pair from mikes only to find out it doesn't work and the I have to pay 25% restocking fee. Let me know.

Thanks for the link 'twomany' - looking at that post makes me think I took a little more off than will work comparing my tank to the one posted in link.

 

[nj1639]

I think part of the issue is that the rubber gasket squishes out too much so maybe some sort of paper gasket would be better? If so, what kind should I look for?

Yep, if the gasket is squishing out then you're overtighteneng. I've been running that set for about six years and now have a second. I had an issue with leaking when I put the first one together......overtightened. When I set them now I watch the gasket and tighten just to the point of squish.

 

[gggGary]

What year tank/petcock sbaugz? That tank was so fuggled so many ways I tossed it on the scrap pile. Couple O boys came and bought some other farkle and snatched it up like it was gold LOL.
Yeah JB weld and epoxy didn't do a very good job of holding on the "custom" flush mount "racing" cap. WTF?

pity pingle doesn't make the adapters with an o-ring groove like they should.

 

[sbaugz]

What year tank/petcock sbaugz? That tank was so fuggled so many ways I tossed it on the scrap pile. Couple O boys came and bought some other farkle and snatched it up like it was gold LOL.
Yeah JB weld and epoxy didn't do a very good job of holding on the "custom" flush mount "racing" cap. WTF?

pity pingle doesn't make the adapters with an o-ring groove like they should.

It's a 1977 xs750 tank but takes the same petcock as the late model xs650's. I know my 1981 xs650 special petcock fit, but of course, I got rid of that petcock a while ago.

 

[sbaugz]

Yep, if the gasket is squishing out then you're overtighteneng. I've been running that set for about six years and now have a second. I had an issue with leaking when I put the first one together......overtightened. When I set them now I watch the gasket and tighten just to the point of squish.

Problem is, if I don't tighten it enough, then it leaks. I tightened it until it just squished out, and now it doesn't leak- but for how long is anybodies guess.

 

[DogBunny]

I routinely blank off one petcock with a steel plate on dual-petcock tanks, and I routinely toss the old o-ring on the stock petcocks. In both cases, I make my own cork-rubber gasket. I use this:
http://www.oreillyauto.com/site/c/d...oap?ck=Search_N0488_-1_511&pt=N0488&ppt=C0137
It has just the right amount of squish, and you can tighten it as much as you want, and it will seal a pretty crappy surface, although I suggest that you clean up the surface as much as possible. For under $6 you will get a supply that will last a very long time. I use this stuff in all kinds of applications, including on the ThermoDipSticks that I make.

 

[weekendrider]

^ +1 . . .