GS500f Carbs Leaking

greyhour · L Plate Warrior Joined: 19 Aug 2020 Karma :

Okay im completely lost, someone please help..

I bought a gs500f 2005 6 months ago running great. During lockdown it was left in the garage for 2 months. After those two months it had trouble starting and ruinning whcih turned out to be one of the two carbs having its float stuck closed. Fair enough, stupid me left the fuel sitting in it. Pulled the carbs, cleaned the jets and needles. Added some injector/carb cleaner to the fuel as well to clean out anything i missed. Ran great for about 1 month. Then the same carb that had gotten stuck closed got stuck open while on a ride. It got stuck open on a hard pull, quite high in the rpm. No amount of smashing the carb with a screwdriver helped. Made it the short distance home and took it apart. Sparkplug was fouled and a little fuel had gotten in the oil. When i took it apart float was not stuck but there was a small amount of debri in the float bowel. New sparkplugs, oil, clean carbs, later everything was working again. Took it for a long ride and evey once in a while (2 hours or so) it would get stuck open for 5 minutes or so but then itd fix itself.

Now i was confused, intermitend overflowing? Now its apart again, ive had a look at the tank, not rusty, clean fuel comes out. Took the filter out of the tank, no holes in the meshing and looking really clean. Ive completely emptied the tank anyway. Taken the seat out of the carb (its always the same carb that is having issues) o-ring that seals around the seat looks good. needle goes into the seat nicely and definitley seals well. Ive used some polishing coumpuond to polish the seat but its closing fine whenever i test it in or out of the carb. Im about to give up, i cant see whats wrong..

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

Mesh fuel filter?

Get a paper element one. Mesh is far too big to catch what you want to catch.

greyhour · L Plate Warrior Joined: 19 Aug 2020 Karma :

Its the one inside the fuel tank as seen in this picture;

https://www.google.com/search?q=gs500f+tank+fuel+filter&tbm=isch&ved=2ahUKEwiZy_T4jajrAhWMgGMGHQShDwIQ2-cCegQIABAA&oq=gs500f+tank+fuel+filter&gs_lcp=CgNpbWcQA1CGkQRYgpcEYPKXBGgAcAB4AIABwwGIAeUFkgEDMC40mAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=2Is9X5n_EYyBjuMPhMK-EA&bih=936&biw=1680&client=firefox-b-d#imgrc=iwVI5dJ8ZmZ2-M

Its more of a very fine mosquito net situation. Ive heard mixed results (running out of fuel issues) about putting an inline fuel filter into the equation since the gs500 is completely gravity fed, but I can give it a try!

jaffa90 · World Chat Champion Joined: 06 Apr 2016 Karma :

You may be getting crap from the fuel tap itself if it has a turn lever? An inline filter would be useful.

greyhour · L Plate Warrior Joined: 19 Aug 2020 Karma :

jaffa90 · World Chat Champion Joined: 06 Apr 2016 Karma :

Test the flow on PRIme, also you can leave on PRIme to test on a run and back on vacuum (ON) for a further test.

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

Also worth mentioning that I would just replace the needle and seats. They're one of those parts that seems to cock around for no good reason. Everything can look fine, you can grind them to get a good seal, and still they stick or leak. Replacements aren't that expensive, and it saves having to remove the carbs any more.

Whilst an inline fuel filter is generally a good idea, it's still fairly unusual for crap to cause much trouble with the float needles. The stream of petrol going past them tends to clean off the shit, even with a really filthy fuel tank.

Also, if it was me, I would just ignore the problem and ride it a bit more. It will probably sort itself out with a bit of fresh fuel and vibration.