Leaky Fuel Tank Petcock 58 R50

I'm a new guy and apologize as I'm sure this has been covered before. When I first turn the petcock on, it leaks badly around the fitting at the tank. After about 15 minutes, it stops completely. I replace the original one with a factory replacement and even have a spare new one in my spares box for the bike. I was told years ago to put the position to reserve when the bike is not in service but this hasn't worked either, it will leak in that position for about the same length of time.

I'm getting the bike ready now to go back on the road with the rebuilt carbs, and would love to resolve this issue forever if possible.

Thanks to all of you for your time.

Also, I'm curious if any other airheads are in my area, Semora, NC, 27343, would like to get more connected in our little community. Please let me know. Thank you.

I'm not exactly sure of the /2 era petcocks but I think it's the same. There are right hand and left hand threads involved. One type is on the tank outlet, the other is in the petcock. I hard washer is sandwiched the two. One must break the petcock up to the tank and then turn the nut to draw the two items to each other, compressing the washer between them. The washer is needed to keep it from leaking. If yours leaks, my thought is that the tank outlet is not completely flat and might have a burr on it, thus not sealing. I had that issue on my /7. I disassembled and used a flat file to make the outlet stub completely flat. It solved me problem.

You should put the petcock in the off position when not in use. If the petcock is in good shape, "off" should stop all flow of fuel. I don't think this will solve the leaking during the first 15 minutes...that's due to as I said some irregularity with the tank outlet stub.

+1 on what Kurt said. Also, there is a fiber washer in there, unless it's been replaced with a new screen/filter which has an aluminum crush washer built in. I don't believe you would use the fiber washer with the new screen/filter style. If so maybe a surface mating issue as well.

jposig said:

I'm a new guy and apologize as I'm sure this has been covered before. When I first turn the petcock on, it leaks badly around the fitting at the tank. After about 15 minutes, it stops completely. I replace the original one with a factory replacement and even have a spare new one in my spares box for the bike. I was told years ago to put the position to reserve when the bike is not in service but this hasn't worked either, it will leak in that position for about the same length of time.

I'm getting the bike ready now to go back on the road with the rebuilt carbs, and would love to resolve this issue forever if possible.

Thanks to all of you for your time.

Also, I'm curious if any other airheads are in my area, Semora, NC, 27343, would like to get more connected in our little community. Please let me know. Thank you.

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FIX: The petcock I installed years ago did not come with new upper and lower fittings or seals for some reason so I had to re-use them. The one I had in my spares box had both the fittings and seals and FIXED the fuel leak issue. I'll follow advice given here and just leave the position on ZU when motor is not running.

Part Number: 16 12 4 084 030 R. Application: Petcock. R51/3-R69S EVER. I paid $ 79.95 for it, but that was back on 03.22.16.