GS1000G petcock repair using the K&L kit

[GS1000G Shopper]

I recently rebuilt- or tried to rebuild- the petcock on my 1981 GS1000G. I expect others may be similar.

After reassembly, I was able to draw air through the fuel line with no vacuum on the vacuum fitting. What this means is that fuel would run out with the engine off.

Unfortunately I didn't do my research here and learn that about 10-15% of the people here have had success doing this rebuild. After taking it apart, I found the piston on the diaphragm was about 1/2mm too short- another member pointed this out in my other thread. Since there is no way to extend it, what I ended up doing was using a larger o-ring to make the seal. I went to McMaster.com and found a set of 25 Viton o-rings for about $10 + shipping. The o-ring in the kit is about 4mm ID x 1.5mm thick. I bought McMaster # 9263K694, which is 4mm x 2.5mm thick, for an effective OD of 9mm.

After replacing the o-ring, I had a good seal. Applying vacuum opened it up, and it also was open in the "PRI" setting.
UPDATE 7/16/13
I have sold out of these. You'll need to order from McMaster.com as noted above.


UPDATE 5/1/13
If you are in Canada or otherwise outside the USA, it is cost-prohibitive to send these, as postage is higher and the money transfer is costly. I have sent 5 of these to member HamamatsuSuzi. You can PM him to get the cost for one if you are in Canada.

Here is a pic of the new and old o-rings so you can see the size difference:

 

[Guest]

You just got to ask yourself how many of those rebuilt kits have been sold that don't work? Probably every one sold fell short of getting the petcock to work correctly, but they're still selling them.

I'm glad someone took the time to really investigate and determine the
1. shortened diaphram piston
2. smaller than stock O-ring.

Now we can focus on the real causes of our failure to get these working again with the re-build kit instead of banging our heads against the wall.

I've had a certain amount of succes rebuilding these, but I only had one kit and I'm not sure if I used the diaphram that came with it or not, mostly the other gaskets and seals and the old diaphrams.

 

[rustybronco]

The diaphragm in my 1000's was still in good shape. So I reused it and installed a new larger o-ring on it, replaced the rubber seal with the four holes in it then went through the petcock with a fine tooth comb renewing all the sealing surfaces properly.