I have a 2005 gs500f that I am trying to save. I bought it from a guy because the gas tank had rusted and he didnt want to rebuild the carb and replace the tank so I got it for 200 bucks. I rebuilt the carb and did all the necessary things and hooked up a gas tank from a old fourwheeler and its not getting fuel from the tank like its going through the petcock but its like its not getting to the carb. So my question is. Is there a pump of some sort or some kind of way the carb get gas to it I only have a gas line going to the petcock from the tank and then another going to the carb. I can spray some starter fluid in the air box and it will crank and I can rev it up once but then it will die.

Is there gas in the carb bowls?

I'd guess float level is wrong, maybe float needles are sticking shut, clogged fuel orifices in carb.

Not sure I will have to look. When I put it all back together the float was moving pretty freely I did rebuild it but I will take a look. So there is no pump or anything that pushes the gas from the petcock to the carb

Plain old gravity pulls fuel from the petcock to the carb. You need to make sure the tank outlet and petcock are above the top of the carb bowl. You can open the float bowl drain screw and get fuel to flow through the float valve. While you are at it if you attach a length of clear fuel hose to the float bowl drain nipple you can use it to check the float bowl fuel level (and float height).

The stock petcock is also vacuum operated to open, so also check to see if that circuit is working.  If no vacuum then petcock won't open, and no gas to the carbs regardless of float.

good point endopotential! I assumed since he said he hooked up an old tank that it was direct to carbs or using that tank's petcock.

If using the stock GS500 petcock, put it on prime to get fuel to flow in the absence of vacuum. Once you get it started once with the vacuum line is hooked up you can switch it back to run and it should keep on working.

Where does the vacuum line run from and to? And alright i will check that out.

Turn your main (frame mounted) fuel tap to PRIME position, this bypasses the vacuum system so fuel will flow.
Best not to keep the bike too long in PRIME pos when it's not running, because it might flood your carbs if left sitting like that.

I have tried starting it on the PRI position and it wont start im gonna get some clear line tomorrow and test and see how much gas is getting in the carbs

Nothing I can add here.........but this tempory fuel tank??

It is vented isn't it?

Yes it is vented the reason im using a temp tank is so that if this thing isnt gonna run or I cant get it running there is no point in me spending 300 dollars on a used tank thats gonna still need some work. I checked the fuel level and its good... Something must be hooked up wrong.

Quote from: Surplus on October 26, 2016, 01:07:20 PM
...spending 300 dollars on a used tank thats gonna still need some work

FWIW I will have a GS500E tank for sale soon, way less than $300, doesn't need any work to be functional (minor dents, finish notwithstanding).

Quote from: Surplus on October 25, 2016, 04:26:44 PM
I have tried starting it on the PRI position and it wont start im gonna get some clear line tomorrow and test and see how much gas is getting in the carbs

Clear hose will only tell you if fuel is getting out of the tank past the tap and down the hose, it won't tell you if the fuel is actually filling the floatbowls.
Just open the drain screws at the bottom of the carbs to see if fuel comes out. Then you'll know.

Yeah I undid the drain screw at the bottom and fuel came out I dont think the fuel is getting through the carbs and into the cylinders. Might tear down the carb again and double check everything and make sure the float level isnt to low. What is a good float height?

Quote from: mr72 on October 26, 2016, 02:43:38 PM

Quote from: Surplus on October 26, 2016, 01:07:20 PM
...spending 300 dollars on a used tank thats gonna still need some work

FWIW I will have a GS500E tank for sale soon, way less than $300, doesn't need any work to be functional (minor dents, finish notwithstanding).

How much and what year is the bike the tank is from? Any rust inside? Im not really concerned about dents and such as time will fix those.

Quote from: Surplus on October 26, 2016, 05:40:13 PM
How much and what year is the bike the tank is from? Any rust inside? Im not really concerned about dents and such as time will fix those.

Dents may be hard to fix any more than they already are. Anyway. No rust I know of and probably $100 plus actual shipping for gstwins members. It's a 92. Probably won't fit with a stock f seat. Pm if you want more details.