Gas leaking from where? (SOLVED)

[Torstein]

Update:

Put the bike together after cleaning out the carb bowls/jets. The floats seemed totally fine, they moved freely, though I didn't check the float height...

Put the bike back together, changed the oil, started it up and it idles at 6-7k, my guess is I have the throttle cable too tight. Is there a good way to know how tight to put it back together? I'm used to working on bicycles, and any cable slack is bad, so I tighten cables a lot. Also, it still leaked a bit of gas, my guess is the floats need to be adjusted. So I'm going to pull it back apart and check the heights. Should have done that originally, but I was just hoping for an easy fix with a stuck float or something. So, back to the garage I go. The saga of the 500 I bought and never rode continues...

[Torstein]

Update:

Pulled the bike back apart, did my best to measure/bend tabs to stop fuel from overflowing from bowls, buttoned everything back up, still leaking. I guess I'll pull it all apart and bend them the other way, I must have bent the tabs the wrong way or something.

Also, I pulled one of my fuel lines off the tank, and there was a metal piece that came with it, is there a good way to reseat the metal piece back into the hole in the tank? Not sure if I'm describing it correctly. It's like a little metal spout that the hose connects to, when I pulled the hose off, the piece came with it, so I just reinserted it and pushed really hard. There seems to be a small leak there now because of this I'm assuming. Goodie, 2 fuel leaks! 

[Big Rich]

In regards to cable slack - there should definitely be a little. With the throttle cable, you should be able to wiggle the throttle tube a little bit before it starts to open the butterfly valves. There should be a spec for slack in the service manual - I think it's measured right by the carbs though?

Have you checked that the float needle is shutting off the gas flow? With the petcock set to off and ONE float bowl removed, push up on the float needle with your finger and turn the petcock to prime. If gas runs past your finger, your needle isn't doing its job. And how are you measuring the float height? There's a very specific way to measure it in the manual, and it needs to be followed to the letter.

[smokestack]

Also, I pulled one of my fuel lines off the tank, and there was a metal piece that came with it, is there a good way to reseat the metal piece back into the hole in the tank? Not sure if I'm describing it correctly. It's like a little metal spout that the hose connects to, when I pulled the hose off, the piece came with it, so I just reinserted it and pushed really hard. There seems to be a small leak there now because of this I'm assuming. Goodie, 2 fuel leaks! 

I think you can pick up a replacement petcock for around $30 on ebay. Pretty sure that brass nipple isn't supposed to come out...   

[gsJack]

I pulled a tube out of a tank petcock years ago and removed it from the hose and tapped it back in tight with a light hammer and it never came out or leaked again.

[lucas]

You can tell if your throttle cable is too tight if you can't wiggle the throttle tube like Big Rich said. Also you should be able to twist the throttle and let go and you should hear the throttle valve clap against the idle screw.

Speaking of idle screws, check that your idle screw isn't turned in too far.

[smokestack]

I started detaching the hoses at the frame petcock and pulling the hoses through... much easier than trying to re-attach them to the tank with that little room to work with. Easier to drain them too without gas flying everywhere.

[Torstein]

Thanks again for the suggestions/ideas. I'll just lightly tap that tap into the tank with a small hammer. I figured it's probably just not seated well enough. The second time I pulled it apart, I took the hoses off at the petcock much easier to work with them this way.

As for the floats... my needles look OK, though maybe the one is just degraded enough for the fuel to leak? Is this common? I suppose I could just buy new needles and see where that gets me.

As for measuring, I got a digital measuring caliper, but was having a hard time lining up exactly where to measure from, I understand it's from the bowl gasket part to the top of the floats, but I couldn't figure out how to get the floats lined up and whatnot to get the right measurement. So at that point, I figured I'd just bend the tabs a little bit to see if it would get the needles to close that tiny amount they are probably off. I may have bent them the wrong way though, so maybe I'll just pull it apart again and bend them back the other way a little bit. IDK... I read guides online and I have a Clymer book but I just couldn't figure out the best way to measure. My bad, I probably did it wrong. I found it hard to keep the floats in 1 position and measure at the same time, seemed like they would move a little bit and then my measurement would change each time because of that.

Good news, is when I put the bike back together this time, I got the throttle cable just right, and when the bike was running, I had a good idle, so I am pretty sure I can repeat that again. I did back the idle screw all the way off and confirmed that it wasn't causing any issues with it, but I appreciate the suggestion there.

I am definitely learning more about how this bike works then I ever did with my other bike, which is both good and bad. Good because I like tinkering and learning stuff, bad because I owned the bike for 1 week before it broke and now it's perfect riding weather and I've been down and out for 3+ weeks now. Boo.. Anyway, back to the garage as soon as I find time.

[smokestack]

I am definitely learning more about how this bike works then I ever did with my other bike, which is both good and bad. Good because I like tinkering and learning stuff, bad because I owned the bike for 1 week before it broke and now it's perfect riding weather and I've been down and out for 3+ weeks now. Boo.. Anyway, back to the garage as soon as I find time.

Dude, I feel your pain. One. Flipping. Thing. After. Another. Going on 2 months waiting on parts and flakey people. Wish you better luck.

[jeZZa]

aside from checking your float needles rember theres a o ring under the seat... if that o ring has faild you will never get the fuel to stop flowing, they should just pull out with a little resistance, if they just fall out then you know the orings are poked

[jeZZa]

http://gstwins.com/gsboard/index.php?topic=56601.0
scroll down about 3/4 the way and theres a lovely pic of the seat and oring

[Torstein]

aside from checking your float needles rember theres a o ring under the seat... if that o ring has faild you will never get the fuel to stop flowing, they should just pull out with a little resistance, if they just fall out then you know the orings are poked

awesome, thanks. i have not checked that specific o ring, i'll make sure to pull it out and take a lookie. that definitely could be the culprit!

[Torstein]

aside from checking your float needles rember theres a o ring under the seat... if that o ring has faild you will never get the fuel to stop flowing, they should just pull out with a little resistance, if they just fall out then you know the orings are poked

this has GOT to be it. I was off of work today, so i tore everything apart again. I was able to pull one of the seats out with almost no resistance, the other one seems to be stuck pretty tightly in there. The suspect "problem" carb is the one with the totally degraded o-ring. yay. I really feel good about this one. That degraded seal HAS to be what is causing my leak. Time to find the part and order up. Thanks!

[jeZZa]

good luck 

[Torstein]

Ugh, I am desperate.

I replaced the o-ring seals inside both carbs (2 o-rings per carb). I replaced the gaskets in both carbs. Put everything back together. Still getting fuel overflowing. Does anyone have ANY other things I can try? This bike is about to get sent to the dump.

[Big Rich]

Snip

Have you checked that the float needle is shutting off the gas flow? With the petcock set to off and ONE float bowl removed, push up on the float needle with your finger and turn the petcock to prime. If gas runs past your finger, your needle isn't doing its job. Snip......

[lucas]

Also if the fuel is flowing even while on On or Reserve you have a problem with your frame mounted petcock.

[Torstein]

Also if the fuel is flowing even while on On or Reserve you have a problem with your frame mounted petcock.

Its not. Only overflows when the bike is running. Ordered new float needles today even though mine look fine.

[Torstein]

aside from checking your float needles rember theres a o ring under the seat... if that o ring has faild you will never get the fuel to stop flowing, they should just pull out with a little resistance, if they just fall out then you know the orings are poked

this has GOT to be it. I was off of work today, so i tore everything apart again. I was able to pull one of the seats out with almost no resistance, the other one seems to be stuck pretty tightly in there. The suspect "problem" carb is the one with the totally degraded o-ring. yay. I really feel good about this one. That degraded seal HAS to be what is causing my leak. Time to find the part and order up. Thanks!

FIXED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! YES!!!!!!!!!!!!!

The fix was on one of my seats that the needles go in, the whole seat was corroded. When I pulled the carbs apart after your original suggestion of checking the gasket on the seat, I only pulled one of the seats off, the other one seemed to be "stuck" in there, so I assumed it had a great seal and the seat was fine. Today when I was tearing them apart again, I took a plyers and yanked the stuck seat out. It was super nasty, totally corroded and needed to be replaced. Upon replacing the whole seat and the o-ring, I put everything back together and she purrs like a kitten. I was able to ride again for the first time in a month and a half. SUPER PUMPED!

Here is what I learned from this experience and any wisdom I would pass along to others that are dealing with a leaking set of carbs.

Buy a carb repair kit, it contains the needles, gaskets, o-rings, needle seats and replace everything in the carb. Use the kit and replace everything in the carb, the kits are cheap and since carbs are finicky and get gunked up super easily, it's worth it to just replace all the small parts that can go bad. If I would have just done that right from the start, I would have fixed the problem right away. The only good thing about this whole experience is that I can now tear my bike down super quickly and put it back together just as easily. Thank you to everyone for all the helpful suggestions while I was troubleshooting my gas leak. You guys rock!

Here she is getting her first tank of gas in a month and a half...

[ShowBizWolf]

HOORAY!!!!!!!   

I am super happy for you Torstein!!! And thank you for sharing your experience and what you found out... surely it will help people in the future!