Dumb question time - why do we GS'ers need a vacuum petcock?
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Wrong. The worst thing that can happen with a damaged diaphragm is fuel being sucked in while running. No full crankase or hydrolock issues. When off, the fuel is blocked from free flowing into the vacuum port. The problem you're describing is typical if you leave any manual petcock on or leave the vacuum operated one in prime.Vacuum may be simpler for the rider, but is mechanically more complex with an extra failure point with the diaphragm leaking. You won't know that it is leaking until you discover a crankcase full of gas or bend a rod on a hydraulically locked cylinder. I don't mind having to remember to turn a petcock off, but it looks like that is the minority viewpoint here. To each his own.Mark
Guys, you're chasing ghosts. The stock vacuum operated petcock is a good design and will last for 30+ years. Quit over thinking a problem that doesn't exist.http://img633.imageshack.us/img633/811/douMvs.jpg
1980 GS1000GT (Daily rider with a 1983 1100G engine)
1998 Honda ST1100 (Daily long distance rider)
1982 GS850GLZ (Daily rider when the weather is crap)
Darn, with so many daily riders it's hard to decide which one to jump on next.;)
JTGS850GL aka Julius
GS Resource Greetings
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Oh it doesn't matter to me at all. My biggest problem with the set up isn't any fault of the set up... its my stupidity when I forget to switch it back from "PRI" to "ON" after I get it started after letting it set for a long time... and finding all my gas from the tank has migrated to the crankcase the next ride. :-(Wrong. The worst thing that can happen with a damaged diaphragm is fuel being sucked in while running. No full crankase or hydrolock issues. When off, the fuel is blocked from free flowing into the vacuum port. The problem you're describing is typical if you leave any manual petcock on or leave the vacuum operated one in prime.
Guys, you're chasing ghosts. The stock vacuum operated petcock is a good design and will last for 30+ years. Quit over thinking a problem that doesn't exist.
I was just wondering is someone makes an electric one.1982 GS1100E "Jolene"Comment
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80GS850GBob
Dang...lets all relax a little....it was just a dumb question on my part...definitely not worth arguing over.
My observation was simply why the suzi system needed a vacuum stop as opposed to all the other brands that don't over flow unless a needle and seat goes bad.
My hondas and kawis didn't need it...just wonder what the difference on my suzis was.Comment
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The simplicity and flow of a Pingel is a wonderful thing.They don't 'need' it, it is just so that riders don't have to remember to shut off a manual petcock after their ride is over. Personally, I prefer the simplicity of a manual petcock but lots of riders don't like having to remember anything so they prefer the no brain required approach of a vacuum petcock.
Mark"Thought he, it is a wicked world in all meridians; I'll die a pagan."
~Herman Melville
2016 1200 Superlow
1982 CB900fComment
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If you have a weak spring behind the diaphragm or a bad o-ring, you can definitely get a full crankcase. I just fixed this issue on my 83. I never experienced hydrolock with it, but I never tried to crank it until I fixed it. The PO reported hydrolock to me though. My diaphragm was porous too, and fuel definitely could pass from the "wet side" to the "dry side".Wrong. The worst thing that can happen with a damaged diaphragm is fuel being sucked in while running. No full crankase or hydrolock issues. When off, the fuel is blocked from free flowing into the vacuum port. The problem you're describing is typical if you leave any manual petcock on or leave the vacuum operated one in prime.https://drive.google.com/open?id=0B9zH8w8Civs8ejBJWjdvYi1LNTg&resourcekey=0-hlJp0Yc4K_VN9g7Jyy4KQg&authuser=fussbucket_1%40msn.com&usp=drive_fs
1983 GS750ED-Horsetraded for the Ironhead
1981 HD XLH
Drew's 850 L Restoration
Drew's 83 750E ProjectComment
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Guest
I am going to guess that the "original design" never made it to production, or maybe it was never released on bikes destined for the US market.
I have never seen a double diaphragm or a one way valve on ANY bike, whether it was Suzuki, Yamaha, Honda or Kawasaki.
Yeah, my observations have been limited to those that were sold in the USA, so I don't know what was offered to the rest of the world.
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Seriously? Those are all they had on GS until 1980. The big original clunky one with the screw on lever retainer.Comment
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80GS850GBob
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I think some bikes use vacuum-operated pumps. some Yamahas..xv250 for one. Looking at its parts fiche, I assume the tap itself is "simple".Comment
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80GS850GBob
Snowmobiles do...they operate on the vacuum pulse. Only thing I'd question is that the application there is two stroke and this would be for four stroke..should work better....Comment
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Agreed, and since I relocated my key to the same area, it's a one-two process to put the key in and switch the fuel on."Thought he, it is a wicked world in all meridians; I'll die a pagan."
~Herman Melville
2016 1200 Superlow
1982 CB900fComment
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