Petcocks leaking despite rebuild??

[ERM83]

the left one has a very slow leak, but the right...is pretty nuts. It only stays off when I turn it right over the faceplate screw between off/on. I just noticed this, being that I took the octy off a few days ago, and replaced my fuel filters just now. only used the left tap with the octy, and it seemed fine...no overflow out the carbs, but I noticed the line from the RIGHT petcock started leaking from the T in carbs 1 & 2, due to said crazy leak. so far, no gas in the oil....

Eric

[skids]

You are talking about a special, so I assume you rebuilt the octopus, right? I don’t know much about specials but I remember some issues with octi rebuild kits not working properly.

[ERM83]

I just got rid of the octy a few days ago...going gravity feed! SO MUCH CLEANER under there...I'm lovin' it. I already had all the habits of using a gravity feed already, so I'm not sure why I didn't do it sooner. HOWEVER - I had no leakage while using it...just when I got rid of it, and started HAVING to use the right petcock. The right side leaks a constant, quick drip of fuel on the off position. it's really strange...that rebuild kit (for both sides) hasn't even been in there a year yet.

[MPittma100]

How To Fix

I just got rid of the octy a few days ago...going gravity feed! SO MUCH CLEANER under there...I'm lovin' it. I already had all the habits of using a gravity feed already, so I'm not sure why I didn't do it sooner. HOWEVER - I had no leakage while using it...just when I got rid of it, and started HAVING to use the right petcock. The right side leaks a constant, quick drip of fuel on the off position. it's really strange...that rebuild kit (for both sides) hasn't even been in there a year yet.

Still leaks? Will have to pull it back apart and look for obvious causes of leaks, put another kit in it, or replace the petcock assembly. Some have fed all 4 carbs off of 1 petcock. And it works. If interested in that, PM Bikerphil.

Good luck.

[red bandit]

Whether you use the right petcock or not I would make sure it shuts off. As they said, take it back apart. You also need to address the leaky T between carbs 1 & 2. You have a couple options there.

[bikerphil]

Yep, take apart and check the rubber disc with the 4 holes in it, probably is cracked.

[skids]

Yep, take apart and check the rubber disc with the 4 holes in it, probably is cracked.

Do the specials have petcock valve handles that are specific for right and left sides? The standards do and if you mix the up, they don’t work properly. If you take the petcock apart, you might want to sand and polish the surface the face that contacts the rubber gasket. With “gravity feed” you will be rotating it and you don’t need a rough surface eating the rubber gasket.

[jetmechmarty]

I know this isn't the issue, but I'll put it here because of the thread title. The petcock and shutoff valve rebuilds kits have an o'ring on the diaphragm assembly that does not seal. A thicker o'ring is required. It may be why so many shutoff valves (octy) get thrown away. It's the same with standard vacuum shutoff petcocks.

[bikerphil]

Do the specials have petcock valve handles that are specific for right and left sides?

Yes they do, they are stamped on the outside center, L + R.

[ERM83]

sorry to be a space case...

still haven't really gotten to tear into the petcocks or not, but I put inline shut-off valves on there just for insurance for the time being. so, I DO know that everything was put back together correctly, but check this out - the right petcock turns OFF (with a VERY slow drip) when I line the tab up with the little SCREW BEFORE the actual off position. that is weird...


Eric

[thumperjsa]

I'm curious what you used for an inline shutoff valve. Is it a manual shutoff or perhaps a 12v model?

Phil helped me with changing over a couple of bikes to one petcock. One 79 Special (no octy) and an 80 Standard. Make sure if you do this, use the left side. I still have the 79 Special setup this way with just the left side feed and it works great.

[Mark_E]

I just got rid of the octy a few days ago...going gravity feed! SO MUCH CLEANER under there...I'm lovin' it.

So, how did you do this? What needs to go where? What gets axed? Here's an image from the Manual.


Thanks much!

[thumperjsa]

You're basically ripping and replacing all those hoses and parts between the petcock and the carb T. Front nipple of petcock, just get a rubber nipple cover. Rear one, run down to the carb T. I also recommend an inline fuel filter. You'll need to shut off the fuel though every time you shut down. Also why it is easier to feed just from the left petcock. The right side just stays off. BikerPhil helped me set that up on my Special.

[SteveO]

Rebuilt the Petcocks a couple of years ago. I can hold the full tank up (off the bike) with the petcocks in the off position, and there is NO Leaks; however, with the petcocks off since January (the last time I rode) I still found gas in the oil.

My next step is an in-line shut-off valve between the petcocks and the Octy.

[skids]

Rebuilt the Petcocks a couple of years ago. I can hold the full tank up (off the bike) with the petcocks in the off position, and there is NO Leaks; however, with the petcocks off since January (the last time I rode) I still found gas in the oil.

My next step is an in-line shut-off valve between the petcocks and the Octy.

So you are trying like hell to keep that octi...