Topic: another petcock question.

[Tnutz]

my petcock on my 76 550 is getting a little damp all the time....I know the tank was replaced by the last owner so i don't know if this is what it had stock, the petcock is the thread on kind with 2 outlet barbs.  i want to buy an aftermarket replacement from z1, does anyone know the threading on the dual outlet petcock?  (my head is swimming from looking through all the petcock threads)

[City Boy]

Have you determined whether the petcock itself is leaking or is it the tank/cock seal?

[Tnutz]

petcock forsure.  it's not bad yet, but i am awaiting the day when it decides to quit...   so i would like to fix it before.

[City Boy]

Hi.Can your petcock be disassembled?If so you may be able to get new rubber internals.

[Johnie]

I would stay OEM rather than aftermarket. But these can be easily rebuilt. At least they are on my 750's. Only 3 gaskets to change. I change the one where the tank and petcock meet, the one under the bowl and the one under the on/off lever. Could it be damp because the bowl on the bottom is loose?

[mystic_1]

On the early 750 petcock and other similar designs that are held on with two screws, you also need to replace the fiber sealing washers under the screw heads, otherwise fuel can leak past the valve into the sediment bowl.  This would not cause an external leak at the petcock but allows fuel to flow when the petcock is off.

mystic_1

[Johnie]

On the early 750 petcock and other similar designs that are held on with two screws, you also need to replace the fiber sealing washers under the screw heads, otherwise fuel can leak past the valve into the sediment bowl.  This would not cause an external leak at the petcock but allows fuel to flow when the petcock is off.

mystic_1

Ah good call mystic. I forgot about those. Those sealing washers mystic is talking about are pretty expensive at the dealer. But you may want to check your local hardware store which is where I get mine. I think they are a fiber type washer. I guess they should be gasoline proof, but I am not sure if mine are and have been fine for 3 years.