Petcocks - fuel filters. 80 GS850G.

[Redman]

My fuel filter is a bit crudded over on the lower parts of the filter, discolored anyway and doesnt run as well if tank low and on reserve, it runs but not as well, not a big problem, but want to do something afore it gets worse. The filter seems like a fragile plastic-fabric that maybe doesnt tollerate much physical abuse to try and clean it. The filter part doesnt seem to be a seperate part that the dealer can get, or there was some reason I didnt get one when I inquired at dealer this spring, dont recall specifiaclly why, maybe too expensive for this dutchman.

I see a few different petcocks (with filter) on ebay from time to time (3 at present). I see that the petcocks for like 82-83 are a bit different than for the 80, and I do recall the one my 82 GS650G being a bit different-smaller. The 80 is a bit bigger and more round, that is: the portion with the lever and diaphram is bigger, like maybe the diaphram in it is bigger.

But anyway, so I am sitting here pondering this rather than rakeing frosted frozen leaves.
My main question is this: Even though the petcock lever portion for the 80 is bigger than 82 or 83, is the filter portion substituable?

[KEITH KRAUSE]

I don't think the plastic fine screen filter comes off.
I've never had to clean one that was really dirty. I've seen them discolor. I have used a toothbrush (lightly) and it didn't hurt the fine screen. I think just "swishing" the filter back and forth in a bowl of cleaner is a safer way to clean it though.
The gas should flow well in reserve or with a low tank. Before giving up on it, I would take the lever section of the petcock apart and shoot some cleaner through everything, followed quickly by a rinse in gas. Then take some monofilament line or wire (gently) and poke into any holes. Then blow compressed air through it. Do this a couple of times. Be sure any rubber parts are in good condition. Some petcock have rebuild kits for the diaphragms, some don't. If your petcock doesn't have a rebuild kit, I would not touch the diaphragm section. If the tank o-ring has hardened, replace it.
If the tank has dirt, clean it out. If no rust, I'd get rid of any in-line filter. The stock petcock filter works fine if the tank is in decent condition.
Then clean out the gas cap venting. Carb cleaner with a spray tube works well. Always follow quickly with a gas rinse. The ball in the vent should rattle easily.
If all this is done, the petcock should work well. If you buy a used petcock, be aware the diaphragm could be drying up. I replaced mine with a Pingel. About $90 including the adapter and shipping. Well worth it if you're keeping the bike.

[Redman]

Oh, if the filter part doesnt come off the petcock unit, then I should not buy the ebay petcock just for the filter part. Thanks Keith, actaully its Thanks Again.

Yah, suppose I should try the dissassemble-clean and/or the rebuild kit before it gets too cold in garage. I got a rebuild rebuild kit some time ago. I was thinking to replace the filter when I rebuilt it, but if the filter isnt replaceable, guess I'll try your cleaning suggestion.

Every once in awhile the petcock leaks a little gas around the lever, leaves a drip smear down the air box cover. And the petcock is all brown discollored.

[KEITH KRAUSE]

I'm not 100% positive about your filter being permanently mounted, just pretty sure. The thing is, the screen is good forever unless it's torn. There's no need to replace it. If anything did get inside it, it would be something very fine and could be flushed out. Just be sure the screen is clean.
The brown color is just gas varnishing. The lever leak is sometimes because the screws are a little loose holding the plate. If tightening them so the leak stops makes the lever too hard to turn, then the rubber disc behind the plate needs replacing.

[Poot]

I have gotten mine replaced...... I have seen very similar looking things at Canadian tire.. check some auto parts stores, or something?

[Anonymous]

I went through the whole petcock rebuilding drill a few years ago on my 1980 GT. To no avail. I bought a new one and there have been no problems since.

The screen is staked in place and is hard to remove, but probably not impossible. May not be worth screwing with.

Vince