Petcock Replacement

[corey]

So I'm replacing my petcocks with some fabricated nipples and some inline shut-offs. The problem I'm running into is sealing the new nipples to the gas tank. I tried using gasket sealer (which is what is suggested in the tech article for this mod/quick fix) but that ended up leaking. So I had some rubber around the garage which I cut to shape and used as a gasket. This held up great for a while, but the gas ate it up, thus its leaking again. :S

So now I'm stuck on what to use. Do you think laying my old petcock oval o-rings on the newly fabricated nipple plates will work? I'm doubtful of this, as my new plates do not have an o-ring channel like the stock petcocks, thus they might slide or vibrate over to far and start to leak. Or is that channel even necessary to seal up the tank? Will the pressure of the gas keep the orings in place? If the o-ring will not work, where is it possible to get a piece of rubber which I can cut into gaskets?


I wish I wasn't such a cheap a$$, otherwise I'd buy the petcock rebuild kits.

[AlanB]

Hi Corey,

Just repair the petcocks!

Are they Standard or Special? The "O" ring round the outside of the control can be replaced with a standard ring, the big washer with the four holes in can be reversed to give a fresh face. If they are specials, that is it; If standards, you may need to look at the diaphragms.

Either way, sounds easier than making new ones!

AlanB

[corey]

Indeed it does sound easier, but I already have them fabbed! I kinda like the look too. Mainly, however, one of the copper nipples out of the old petcocks fell out in travel (one that provided the Prime fuel flow), leaving me with a slight leak. Do you know where I can get one of those quarter inch copper nipples? Then I'd be cool with using the old petcocks.

I have thought about plugging the prime option with some solder, or something, as I don't have an octopus anymore. Then I could use the old setup without any worries.

[TopCatGr58]

Corey,

The problem you had was you used some natural rubber which won't work as you found out. Go to the hardware store, and get some NEOPRENE rubber washers that you can cut to fit your petcock plates, and that will seal it. Are you using the felt washers for the screw/bolts? IF not then it can leak there as well.

T.C.

PS, I've heard folks using JB weld to refit one of those nipples back into a petcock, but IF you don't want to use that opening, you can probably plug it with the same stuff!

[corey]

Ah, the magic of JB. He and this Duck fellow really are something, no?

I spent a while researching rubber on Google earlier trying to figure out which would be best. I'm glad you led me in the right direction. When I made those gaskets I sorta figured they wouldn't work, but I was (again) being cheap and in a hurry.

So now the gameplan: get some neoprene to get 'er rolling, then play with the stock petcocks with Mr. JB. Thanks to both of you for your thoughts!

[AlanB]

Hi Corey,

If your bike has "Prime" it is a special, so no diaphragms in the petcock. If the valves are A1, you should never get fuel down the prime line unless the control is turned to prime...... But I wouldn't like to trust it.

I had to alter a set of Kwak cocks for my bike (long story......) I pulled the brass nipple out of one side, and found that a short section cut from the shank of an M8 bolt was a pretty good fit in the hole. I used a smear of two part epoxy to glue it in about ten years ago; it is still good.

AlanB

[Ken Talbot]

Originally posted by AlanB
If your bike has "Prime" it is a special,

I think Alan meant that if your bike has "off", it is a Special. Specials have On, Off, Prime, and Reserve. Standards have On, Reserve, and Prime.

[AlanB]

Hi Ken,

I actually meant that if it has a seperate prime nipple which you can block off, it must be a Special, but I was too lazy to type it all out.......

Sorry!

AlanB

[corey]

This is all correct, Special, as my signature implies. I had the primes blocked off with a short hose which was stopped up with a bolt and a rubber cap. The whole prime assembly shook out though, and since the cocks were faulty, it leaked.

I'll let you all know what I do with it. I plan on getting it done for good today.