So I got the tank completed and have put the bike back together, only to discover that it's leaking at the petcock ,

The leak is coming from around the inside of the ring, like I don't have a good seal against the o-ring.

I have replaced the screen, the o-ring and the rubber housing for the petcock's brass tube. All should be good.

Note: I got some POR 15 on the threads. I have been carving it out of the threads now for a bit. The petcock goes on just fine, tightens up like you would expect it to. I can tighten it pretty aggressively, and the petcock seems to be locked down against the tank, so I can't figure out why it's leaking. I got every bit of it out of the o-ring channel and it's flat and clean with good mating surfaces.

I'm damn near ready to silicone the whole junction and call 'er quits. Got any suggestions before I pursue that course?

 

Just had a thought - am I tightening it down too much? Can you crank it down and distort the O-ring?

I remember when I removed it the petcock wasn't on too tightly.

 

Yes, you can. I am not sure if that bolt(s) has a torque value, but I know the FPR on my F4 does, and if you over tighten it then you can cause that oring to fail because there is a certain pressure rating (torque) that is supposed to be applied to it causing a specific stretching of oring to fill the gap. I would check first and if not work your way up in small incriments testing each time. You may also have damaged the oring you just replaced by overtorquing or tightening, whatever you want to call it.

 

So I was overtightening it, and I still had enough POR-15 crap in the threads to make the petcock seat at an angle. Half an hour with a dental pick and I was clean enough to make a go of it.

Sadly, the rubber on the inside of my petcock failed. Gas was dripping out of the riveted panel due to the pressure; I also think my gas tank vent may have gotten blocked by something during the tank reconditioning. I blew it out with the tank on its side and my air compressor at max - it was locked up, then it finally opened up. I may try it again tomorrow to see if the clearing of the tank vent would prevent that leak.

If all else fails, I'll just buy a new petcock... next month when I get paid.

 

I hear you. Its always something it seems when your messing with these older machines. The good thing that comes of it at least is a like new part/component that you can basically forget about for a long time. It just sucks what they cost . In due time mate.

-Poss