12 volt fuel shut off valves? Because.. that gawd awful vacuum petcock

[bobgroger]

Rebuilds are unreliable. Get a new petcock and be good for another 30 years. The stock petcocks don't fail when new.

+1 million. Rebuild kits suck.

[bobgroger]

...sooo nobody really knows what makes them fail, right? They just last around 2-3 decades? (because then mine would be due methinks...but I see no sign of them wearing out)

They fail because of old brittle rubber, just like the carb o-rings. And tires. And brake lines. Rebuilding them would work if the replacement parts were correct, but they aren't. The o-ring is too small, and the diaphragm doesn't seal, at least for long. Suzuki used to sell the rubber parts, those should be better if they are still available. You probably won't know it has failed until your crankcase fills up with gas, followed by a puddle of thin oil coming out your shifter seal.

[bwringer]

Rebuilds are unreliable. Get a new petcock and be good for another 30 years. The stock petcocks don't fail when new.

Vacuum petcocks are pretty dang reliable. The problems typically only show up after 20+ years and when people purchase junk aftermarket rebuild kits trying to fix them.

And again, there is a check valve built into the back cover of the leverless petcock and when that fails you got no prime.

Yep and yep.

Quite frankly, I'm astonished you got any use whatsoever from a rebuilt petcock. You're very lucky there.

Slap a new one on, and sometime around 2050 it will probably fail. Such a hunk of junk -- only lasting 30+ years of being submerged in crappy gas.

Oh, and guess what material is inside an electric valve doing the sealing? That's right, the same good old Buna-N rubber...


Anyway:

http://www.dan-marc.com/79-afc11112.html

[Nessism]

They fail because of old brittle rubber, just like the carb o-rings. And tires. And brake lines. Rebuilding them would work if the replacement parts were correct, but they aren't. The o-ring is too small, and the diaphragm doesn't seal, at least for long. Suzuki used to sell the rubber parts, those should be better if they are still available. You probably won't know it has failed until your crankcase fills up with gas, followed by a puddle of thin oil coming out your shifter seal.

I rebuilt the petcock on my KZ with OEM Kawasaki parts and the petcock works perfectly. I wish Suzuki sold proper petcock rebuild parts because if they did we probably wouldn't be having this discussion.

[chuck hahn]

For 4 dollars this may be well worth a test run.

https://www.ebay.com/i/112271196753?chn=ps&dispItem=1

[Steve]

You got "only" 22 months from your rebuilt petcock?

Congratulations.

Most people can't even manage to get 22 DAYS from a rebuild.

You want to go electric? Great. There have been some suggestions here on where to source some parts. Kawasaki used an electric valve to supplement the vacuum petcock on the early KZ1300. One of the popular mods on the KZ1300 forums is to get rid of the "$)*&^%$&*" electric valve. I never had any problem with mine, but I only had the bike for about 4 1/2 years and 77,xxx miles.

You should also know that the petcock used on many of the '80 model GSes was thankfuflly a one-year-only device. They soon saw the error of their ways and went back to a proper device. The problem is that the bolt spacing is different, so you can not simply get a petcock from a different year, unless you also change the tank. Then you run into problems like LOCATION. The outlet might be in a different location and simply won't fit on the bike.

Your best solution is to source a brand new OEM petcock. Screw the price, you buy once, you cry once.

.

[jabcb]

If you want to go the supplement route, Pingel has an inline vacuum valve.

http://www.pingelonline.com/pc_product_detail.asp?key=3CCC32F0434D41F0B6C89EC32D85EB11

[gsrick]

...sooo nobody really knows what makes them fail, right? They just last around 2-3 decades? (because then mine would be due methinks...but I see no sign of them wearing out)

I think the fuel here in the states does effect them. It effects everything rubber, that's why I try to use non-ethanol fuel.

[chuck hahn]

But look at the price of the Pingles...better off buying OEM and saving money.

[Gorminrider]

well, i guess if you found a little solenoid suitable for fuel, wiring it in would be pretty simple...just choose any orange wire +colour stripe from the fusebox...these'd only be live when Key-on... Turn key off, solenoid closes. Looks like some lawn tractors have them.

[jabcb]

But look at the price of the Pingles...better off buying OEM and saving money.

Its a good time to buy a spare GS petcock when you notice the prices start rising a lot. Suzuki jacks up the prices for old NOS parts when the inventory gets really low.


I just bought a Pingel vaccum petcock to replace a leaking stock petcock on a two stroke. Suzuki still has the NOS petcock but the current list price is $425. So the Pingel was a cheap alternative that was designed for modern crap gas.


I’m actually fine with Suzuki’s strategy because it keeps the last few that have for the restoration show bikes.

[scratch]

You got "only" 22 months from your rebuilt petcock?

Congratulations.

Most people can't even manage to get 22 DAYS from a rebuild.

You want to go electric? Great. There have been some suggestions here on where to source some parts. Kawasaki used an electric valve to supplement the vacuum petcock on the early KZ1300. One of the popular mods on the KZ1300 forums is to get rid of the "$)*&^%$&*" electric valve. I never had any problem with mine, but I only had the bike for about 4 1/2 years and 77,xxx miles.

You should also know that the petcock used on many of the '80 model GSes was thankfuflly a one-year-only device. They soon saw the error of their ways and went back to a proper device. The problem is that the bolt spacing is different, so you can not simply get a petcock from a different year, unless you also change the tank. Then you run into problems like LOCATION. The outlet might be in a different location and simply won't fit on the bike.

Your best solution is to source a brand new OEM petcock. Screw the price, you buy once, you cry once.

.

Thanks to everyone for the suggestions and as Steve mentions above the some of the 80 model GS vacuum valves were not the best design and were known to be problematic... and they were changed. That's one of 3 reasons why I was thinking of a electric mod. There are other solutions but, in the spirit of exploration, I started the thread.

In the meanwhile, I'll rebuild the old one, kit gets here tues and my gal will be on the road again... I've had good luck with rebuilds and no, I don't expect the rebuild to last forever... hopefully it gets my gal's ride functional till winter.

I also have another 80 GS550 project bike in the work's now and I'll try the electric valve on that first based on some of the links and suggestions here... (before sending her out on the road with an untried mod.)

It may take a bit because it's third on my projects to complete list and, still need an engine to put in it and it's been something I slowly chip away at, (mounted rear brakes yesterday) But when I do, I'll post my results... thanks to everyone who entertained the idea with a good sense of humor and open mindedness.

[Nessism]

The rebuild kit you purchased will not fix the check valve built into the petcock's back cover. If that check valve doesn't operate properly, neither will the petcock.

[JJ]

Your best solution is to source a brand new OEM petcock. Screw the price, you buy once, you cry once.

.

Amen... I tried a rebuild kit on my GK. It lasted a week. I ordered and installed an OEM petcock. It has yet to give me any any problems after 6 years. Bite the bullet, buy OEM, and be done with it for another 30+ years.

[greg78gs750]

another rebuild, huh? mmmkay.