petcock nightmares

[94ta]

Im really getting sick of this bike and its personality. It took me to the edge today after I ended up getting about 4 tablespoons of gasoline straight into my eye.

Bought a brand new petcock but its the wrong size. The holes are to far apart to bolt it to the tank.

So then a petcock rebuild kit was purchased. It came, i put it in, nothing different. It is ALWAYS flowing fuel through the petcock. Its supposed to be vac operated and im under the impression that if you unhook the fuel lines, fuel shouldnt gush out from it. This is also a problem when the bike isnt running, and when it is good old #2 carb is dumping fuel. I spent 235$ on a newly used set of carbs on ebay. The ones i had had a few springs missing and needles and adjustment screw tips broken. The bike runs with the new carbs, it idles high even when i adjust it and when i rev it the revs just hang. it will take 5 seconds if you blip the throttle to 3000 for it to fall back down to 1400ish.

My only guess is the petcock is totally messed up or im missing something somewhere. the diaphram isnt ripped or anything, and to the best of my knowledge its assemebled correctly. The pet cock, then the plastic spacer peice, and then the diaphram, then the spring, then the cap with the vac line. thats the only way it will go together.

No matter what way i assemble it or what parts i use, it just wont stop fuel from flowing.

What do i do?

Thanks

[Tom R]

Do you have it in the prime position? What bike? What petcock?

The hanging idle sounds like a vacuum leak and is probably not petcock related.

[bobiii84]

Yeah I would check to make sure it's not on prime like he said. If you read some posts on this site about petcocks I think you will find a lot of people only use oem. As a matter of fact, I just bought one today that is oem so I don't have the headaches you're talking about. Good luck!

[Tatratbiker850]

Definetly the only reason it is always flowing is its in prime and not the on position which is with switch going up and down not to the left or rt. If # 2 is flooding out the vent line when its running, you got a carb issue. Most likely the "air mix" screw is not set correctly. The carb rebuild section fixed this problem for me. These bikes can be a pain! Dont go throwing money away before you do some extensive reading on this site. Trust me, i have plenty of holes in my walls from the frustration my 850 causes me. Damn bike still wont even start..

[Steve]

What do i do?

One of the FIRST things you could do is give us a clue what bike we are discussing.

.

[rustybronco]

If # 2 is flooding out the vent line when its running, you got a carb issue. Most likely the "air mix" screw is not set correctly.

The 'air mix' screw as you call it, isn't even remotely connected to the reason fuel is coming out the vent line.

[allojohn]

Your bike is an inanimate object. If things are right it will run right. You must take your time, be methodical and follow the checklist on BassCliff's site. Buying a petcock which does not fit is not the bike fault. The carbs you bought on ebay must be checked thoroughly - they may have all sorts of problems. There are no short cuts. Sorry but this is the only path to success.

[sedelen]

Sometimes there are no "quick" fixes. Since we don't know what bike we're talking about, it's hard to suggest very much. If it were me, I'd start with the petcock.
This might help.

http://members.dslextreme.com/users/storagecliff1/images/suzuki_petcock_rebuild.pdf

[94ta]

Oops, cant beleive i forgot to tell you what bike, its a 1979 gs1000

Prime on and res all let fuel freely through the petcock.

The bike has the conical air filters, not a stock air box.

The thing im worried about is BOTH sets of carbs did this. It wasnt overflowing the vent line but the overflow nipples underneath the carbs. both sets of carbs did this.

I think the hanging revs are from the stock size jets and the conical air filters.

No matter what position the petcock is in it always flows fuel like theres nothing stoping it. With the petcock assembled i can blow straight through it in any position as well. The Aftermarket one that doesnt fit, this isnt the case. When I try to blow through it i cant.

Ive built a 94 trans am, cam, headers, valve train, stallconverter. Im not a mechanical idiot, this bike is just cursed haha. Im not throwing money at it just to do it. Right now the part in question is the fuel petcock. If i can blow through it and it flows gas through it in any position, then it cant be right...correct?

[allojohn]

The petcock is knackered. Buy a new oem about $90. And it sounds like you have some sticky float valves. Take the bowls off the carbs and investigate.

[BassCliff]

Hi,

See your "mega-welcome" in this thread: http://www.thegsresources.com/_forum...d.php?t=172452

Follow the links. Read the lists of required maintenance tasks. Read the guides on my website. Read your manual. It's a machine and you can fix it.


Thank you for your indulgence,

BassCliff

[sedelen]

OK, we know the year and the size, now how about the model?

It's not uncommon for the the carbs to overflow as long as there's gas free flowing to them with the engine off. States this on the caution on page 18 of the '79 GS1000/GS1000E owners manual (link below). Also, while you're on that page, is that the type of petcock you have?
It is possible that your carbs are OK, mine overflows if let in PRIME, so I try not to ever do that. So, now the main focus is that petcock.

http://www.mtsac.edu/~cliff/storage/gs/GS1000E_Owners_Manual_79.pdf

[SqDancerLynn1]

Get a universal replacement from www.Z1enterprises.com

http://www.z1enterprises.com/Petcock-vacuum-Suzuki-1715.aspx

Any carbs bought on Ebay would need to be serviced !!

[sedelen]

Get a universal replacement from www.Z1enterprises.com

http://www.z1enterprises.com/Petcock-vacuum-Suzuki-1715.aspx

Any carbs bought on Ebay would need to be serviced !!

I'm not so sure if that petcock would fit a '78 GS1000C or E model, doesn't state so, just GS1000GLX/SZ models (but then again we don't know which model he has). Is 44mm the right spacing between the bolts for a '78/'79 GS1000C/E? I'm not sure.

[BigD_83]

Oops, cant beleive i forgot to tell you what bike, its a 1979 gs1000

Prime on and res all let fuel freely through the petcock.

The bike has the conical air filters, not a stock air box.

The thing im worried about is BOTH sets of carbs did this. It wasnt overflowing the vent line but the overflow nipples underneath the carbs. both sets of carbs did this.

I think the hanging revs are from the stock size jets and the conical air filters.

No matter what position the petcock is in it always flows fuel like theres nothing stoping it. With the petcock assembled i can blow straight through it in any position as well. The Aftermarket one that doesnt fit, this isnt the case. When I try to blow through it i cant.

Ive built a 94 trans am, cam, headers, valve train, stallconverter. Im not a mechanical idiot, this bike is just cursed haha. Im not throwing money at it just to do it. Right now the part in question is the fuel petcock. If i can blow through it and it flows gas through it in any position, then it cant be right...correct?

Next time you have it out, pull it apart in the order you have it, snap and post a pic.

I'm not sure you do have the petcock together properly. It could just be me, but your description makes it sound like the spring is not in the right place. On my 83 650G (admittedly a different petcock than the one on your '79), the spring sits between the metal barrel in the middle of the diaphragm and the plastic barrel of the petcock "switch". That way it opposes the action of the vacuum to close the diaphram when there is no vacuum applied.

I can post a pic of that for you tonight as I currently have no fuel in the tank as I sort out my own running issues.