Replacing fuel petcock (quick questions)

[Fenixgoon]

My 82 GS650G has 8700 miles on it and is currently undergoing a bit of an overhaul. Is it worth replacing the fuel petcock?

I am going to clean my gas tank, and since I have to take everything off, I figured I may as well replace it since they seem to go bad after a while.

Do I need to order the petcock only, or do I need the extra stuff in a repair kit as well?

(petcock) http://www.z1enterprises.com/detail.aspx?ID=1715
(repair kit) http://www.z1enterprises.com/detail.aspx?ID=1507


Thanks GSR, you guys always rock

[MelodicMetalGod]

Replacing the petcock on the my 550 when I got in 2006 was the first order of business. Just ordered the OEM assembly from my local dealer and it came with everything needed to install. Simple, easy and has worked perfectly from the day I installed it. If you're having any issues with the unit, I highly recommend forgoing a rebuild of the original and biting the $$$ bullet for a new assembly.

Best of luck!

[chuckycheese]

Petcock

That's a 'stand alone' job and not difficult to do even if it's the only thing you're doing. If it works well, I wouldn't even consider replacing it.

[argonsagas]

Except for the possibility of improving your peace of mind, there is no overly strong reason to do it as they can work well for many years.

"It it ain't broke, don't fix it."

[rphillips]

If it ain't broke, don't fix it. If it is broke, I would recommend a kit. Very little can go wrong with the housing, it's just a hunk of aluminum. The kit has all the working parts. Just my opinion.

[duaneage]

Clean it and rebuild it. If it has a problem you can always go manual and use PRI for fuel on and then turn it off. Just plug the vacuum tap from the #2 carb.

[Budge]

More info please?

Out of interest, having just got my 83 GS550esd, what are the symptoms of a bad petcock. Think I may have a problem there so the info would be great from you more experienced GS guys.

[ryonker]

Out of interest, having just got my 83 GS550esd, what are the symptoms of a bad petcock. Think I may have a problem there so the info would be great from you more experienced GS guys.

1. Bike doesn't run (might run on prime)

2. Bike runs, but poorly

3. Cylinders are not all firing

4. Fuel dripping out of carb overflow and possibly out of exhaust

5. Gas in crankcase....oil leaking out of engine gaskets

[Budge]

Thanks, the bike was on reserve when I got it back from the shop. Thought that was an error so set it back to on. Next ride and she started breaking down a bit and didn't want to idle. Smells a bit fuelly too. Have put it back to reserve and had no probs running it in the garage. Will be a couple of before I get a good ride on it to test it out properly. I'm hoping it's something simple like a petcock and not carby. The stator and RR voltages check out OK.

[Nessism]

General GSR recommendation is once your petcock starts to malfunction, just ditch it and get a new one. Many members here report poor results with rebuild kits for some reason; could be due to low quality of the rebuild parts, or wear and corrosion on the petcock body. Personally, I've never seen a properly complete petcock rebuild kit that has the proper parts for the later, small lever type petcocks.

Common problems for petcocks is a hole in the diapharagm, resulting in dumping fuel down the vacuum line and into the engine, fuel that will not shut off when vacuum is removed, and a petcock that will just not flow enough in one of the normal positions.

My opinion is to go ahead and remove the petcock and take it apart. On the small lever type petcocks, the small O-ring on the diapharagm plunger is often hard indicating it's near the end of it's life. You can purchase just the diapharagm and small o-ring from various sources, or just look for a Viton O-ring if the diapharagm is in good condition. It's a gamble but worth taking the chance for some if money it tight.

[Pete Logan]

I'm hoping it's something simple like a petcock and not carby.

If switching to Reserve or Prime fixes it, then it's likely to be the petcock IMHO.

The thing you should check first, though, is that you have enough fuel in the tank to run on On.

[duaneage]

My Yamaha has a vacuum petcock and the fuel does not completely shut off, I have to store the bike on the centerstand to prevent it from draining in the crankcase. But as fuel evaporates from the bowls it is slowly replaced with new gas from the tank so in theory it wastes fuel

I agree that cleaning rebuilding isn't always going to work. I have seen petcocks so worn out the gas leaks past the knob. They are not cheap but can be had through aftermarket retailers.

The petcock is an important safety device so a properly functioning one is essential.

[Budge]

You know I think the petcock is worth changing. I suspect some gas in the oil too as the exhaust is a bit fumey. Any idea on the price of a new petcock? I'm coming over to Hawaii next month so I'll try and buy the bike spares I need then. Hard to get some things in Oz.
I'll probably do a ring change on the pistons when I get time too, are standard rings easy to find in the US, I only found a .5 oversize set here in Oz, but they are cheap at $30. Don't really want go for a rebore though, just a lipping and a hone if I can get away with it.

[rphillips]

If a petcock is leaking around the knob (lever) the "O" ring behind the knob is bad. Just my opinion

[Fenixgoon]

well, once i get the carbs back together and the gas tank cleaned, i'm just gonna see what happens. if it works ok, then i'm good to go if not, ordering a replacement petcock is no big deal, either.