Carb Questions

[plumbergs]

Hi,
I recently picked up a 1980 GS 1000 which isn't running. Please forgive my ignorance concerning carbs as I'm no mechanic.

When I got the bike home, I tried to fire it up but no luck. I checked the plugs to see that it was firing and it was.. but they were dry so its not getting fuel. I pulled off the tank and sprayed some starting fluid in the line that feeds the carbs. Nothing. Then I noticed two other lines connected to the carbs on each side of the main fuel line. They are longer than the fuel line in the middle and not connected to anything on the other end. They just run up the backbone of the bike under the tank. Just for the heck of it, I sprayed some starting fluid in one of them and it instantly fired up.

So my question is this: What are those two lines for?

Also, and idea why its not getting fuel from the middle line coming from the tank? Suggestions?

Thanks


Here's a pic I found on google showing the lines I speak of.

 

[Guest]

They're vent tubes. They are doing just what they are supposed to do.
I wouldnt think spraying starting fluid in them is a real good idea.
Welcome!!

http://members.dslextreme.com/users/storagecliff/images/hose_locations.html

 

[Guest]

The picture shows a line that is marked "fuel tank" but that is NOT your fuel line, that is your vacuum line. Your fuel line is the larger line shown in the photo that is pointing down in the picture. To check that the carbs are getting fuel the best method is to open the drain plug on the bottom of the carbs and see if fuel comes out. If there's no fuel it could be your petcock is not working properly, try the different settings 'prime', 'reserve', 'on' and see if any other those work (maybe your petcock is plugged?), the fuel line for some unknown reason is plugged (very unlikely as it's a big line). And if the bike is new to you and hasn't been running for a bit more than like you're going to have to tear them apart and rebuild them. I guess there's always the possibility you were out of gas or at least low enough that you should have been on reserve?? lets see some pictures of this great bike. The 80/81 1000 is the next bike I want to get, congratulations and welcome to the site.

 

[plumbergs]

Thanks for the welcome! I'll try to get some pics up soon.

I labeled the wrong one in the photo, sorry bout that.. I know the smaller one is the vacuum line.

The petcock is definitely working. I tested it by connecting a line to where the vacuum line goes. If you suck on that line, fuel flows out of the petcock as it should.

Thanks for the replies. I will try opening the drain plugs on the bottom to see if fuel comes out. If not, I'll tear them apart and clean everything.

 

[plumbergs]

They're vent tubes. They are doing just what they are supposed to do.
I wouldnt think spraying starting fluid in them is a real good idea.
Welcome!!

http://members.dslextreme.com/users/storagecliff/images/hose_locations.html

Thanks for that link!

 

[chuckycheese]

GS1000 carbs

GS1000 carbs

Those carbs might be from a '79 model....but they're not from a 1980 model.

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. plumbergs,

Yours are the VM carbs used on early GS models. The "Where Do These Hoses Go?" page on my website is for the CV carbs on later models. They are similar except that the petcock gets it vacuum from the #3 carb on the VM rack, instead of the #2 carb like on the CV rack. (The carbs are numbered left to right as you are sitting on the bike.) The gas input is there between the #2 and #3 carbs. The vent tubes are between 1-2 and 3-4. The VM carbs should also have individual drain tubes on the bottom of the float bowls. But I'm no carb expert.

Anyway, let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[plumbergs]

Those carbs might be from a '79 model....but they're not from a 1980 model.

Yeah, thats just a pic I found on google for illustration purposes.. My carbs are exactly like the one on BassCliffs page.

Hi Mr. plumbergs,

Yours are the VM carbs used on early GS models. The "Where Do These Hoses Go?" page on my website is for the CV carbs on later models. They are similar except that the petcock gets it vacuum from the #3 carb on the VM rack, instead of the #2 carb like on the CV rack. (The carbs are numbered left to right as you are sitting on the bike.) The gas input is there between the #2 and #3 carbs. The vent tubes are between 1-2 and 3-4. The VM carbs should also have individual drain tubes on the bottom of the float bowls. But I'm no carb expert.

Anyway, let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

Thanks for the info, the welcome, and all the information! I've already added your page to my favs. Thanks!