78 1000 Brand New Petcock leaking

[portdave]

I just finished treating my tank with evaporust and wanted to get some gas in there right away so I put the petcock back on and it started leaking from the fuel nipple. I took it apart and tried to clean it but it still kept leaking. Drip, drip, drip.

I remembered I had a brand new one from Suzuki for a 78 750 that I dont have anymore so I put that one on. Same thing. Keeps dripping. I put the vacuum line and pulled a vacuum and it flowed out full but would never shut off.

Any ideas?

 

[steve murdoch]

Very odd that a new and old petcock would leak.
Are sure that it is dripping "from" the new fuel nipple and not from the tank seal and "off" the fuel nipple?
Maybe the rubber seals in the new one have shrunk while sitting on a shelf for 30 years and will swell/seat after a gas soak.

 

[portdave]

Hey Steve,

Yes it is strange for sure. I am thinking there are minions in my garage. I did look carefully and made sure it was dripping right at the fuel nipple and not the bolt holes or seal. I might have to try soaking the rubber parts in gas for awhile. It was in my attic in a box for a few years. I was also wondering if it was more the diaphragm area or the front of the petcock with the supply channels that is causing it to leak. I hate to replace the rubber parts on a brand new petcock.

Thanks.

 

[tkent02]

Does Evaporust hurt the rubber parts? I wouldn't have thought so.

 

[portdave]

I dont think they do either but I had pulled the petcock off prior to using evaporust and plugged the holes. Thx.

 

[barnbiketom]

you have the bolt sealing washers on it??? maybe it's leaking there and not the nipple?

 

[portdave]

I actually wiped the bolts with a paper towel to make sure and they were dry. It is for sure coming from the fuel nipple. Thx.

I do need some of the those washers if anyone has a good source. Right now I am using a rubber and metal washer combo but they are holding up.

 

[tkent02]

I have used hardware store washers with O rings built in, it worked fine.

 

[portdave]

I just tried looking at my local ACE but they did not have any. I will have to try some other places. Thx.

 

[Big T]

Dave

Leaks usually come from one of 2 places:

the rubber disc with the 3 holes in it that is behind the handle
The needle valve is controlled by the diaphragm

I can see the old one being subject to ethanol deterioration, but not the new one

 

[hannibal]

I just tried looking at my local ACE but they did not have any. I will have to try some other places. Thx.

Someone linked to these from Home Depot. At least I think it was the 1/4" version. I just checked and I bought the #12 size. They still fit the 6mm petcock bolts and they're just a bit smaller than the 1/4" washers. Haven't installed them yet.

 

[60ratrod]

looks like you can get brand new gaskets from partzilla. but if the sealing washers are holding up just fine, i'd use those.

 

[portdave]

Dave

Leaks usually come from one of 2 places:

the rubber disc with the 3 holes in it that is behind the handle
The needle valve is controlled by the diaphragm

I can see the old one being subject to ethanol deterioration, but not the new one

This is what I thought also. I just soaked the 3 hole disc with gas and reinstalled it but that did not work. Still leaking. I may just have to order the new gaskets or a rebuild kit (which I thought would be worse) and see what happens. Thx.

 

[portdave]

Someone linked to these from Home Depot. At least I think it was the 1/4" version. I just checked and I bought the #12 size. They still fit the 6mm petcock bolts and they're just a bit smaller than the 1/4" washers. Haven't installed them yet.

looks like you can get brand new gaskets from partzilla. but if the sealing washers are holding up just fine, i'd use those.

Just to make sure I went ahead and found some of the 1/4 ones like the HD ones locally today. I put them on and no leaking at all from the bolts. (I will get the oem ones on my next suzuki order)

Still leaking from the fuel nipple. Back to the drawing board.....or parts supply.

 

[portdave]

Well I just looked and you cant get the diaphragm as a part by itself on the petcock so I have to try a rebuild kit.

 

[steve murdoch]

The rebuild kit for the GS1000 petcock did not work for me, of course that was a 30 year old part.
I would hate to take apart a brand new petcock but if you are going rebuild, i would go with the 750.
Good luck.

 

[portdave]

Thanks Steve.