I am in the process of overhauling the bike I bought few weeks ago. One carb is cleaned, another is soaking.

I diassambled the petcock and saw that vacuume holes had debri from rubber hoses. I removed what was on the top of the small round white plastic plug with five holes in it, four smaller ones and a larger one in the center. However, I can see and feel with a 0.5mm pencil that there is more rubber underneath of the plastic. Ideally, it would be best to be able to remove the plastic thingy and clean everything, but I don't know if it can be done.

Did anybody successfully serviced petcock? It would be a shame if I would have to toss away this one and having to shell out $50 for the new one just because there is a bit of rubber stuck here and there.

Jenya

First the one about strap-ons and cameras, now one about servicing your petcock? What's become of this forum?

I used a small drill bit. I figured either I am going to crumble wahtever is in there into small pieces or drill bit will remove it as it normally removes material when being used for drilling holes. Well, it sort of did. It wound onto itself the gunk that was inside.

http://culbertfamily.com/jenya/gs500/dirty_petck.jpg

And that is not even all of it. Perhaps, that was the cause of the fuel starvation I experienced few times.
And, btw, what is that gunk? Where did it come from?

Jenya

so nobody can tell me where that gunk could have came from?

Jenya

I rebuilt 3 petcocks before one worked.  my experience is that the crud I found inside one of the units was from a sealant that a previous owner used to try and reseal the unit. the best way to test them is to see if they will hold vacuum with a mighty vac hand pump.  if not replace or attempt a rebuild (worst thing may be that you learn how they go together).

The GS is one of the few bikes that you can't buy a replacement diaphram for the petcock

jenya, are u like a mushroom hunter or something?

Yes, I go muchroom picking every Fall. Living in rainy WA, one feels obliged.
I am down to the last three jars of the last season pickings.

Jenya

oh my.  i detest fungi.  looks like u have fun with it tho! good way to get in touch w/ nature

If sock petcocks are such a PITA, is it possible to install some other petcock and mounts on the frame and is servicable?

Jenya

some people have tried the pingle petcock.  its different then our petcock.  the gs is vacuum fed and there are ways to bypass it if need be.  search the boards for pingle