GS500 leaking fuel

[FollowingGhos...]

Hi all,

Got a 2002 GS500 that's developed a nasty habit of letting fuel pile out of it.

In theory, the fuel tap is vacuum operated and shouldn't allow this to happen when it's in the 'On' position as there is now vacuum when the engine isn't running.

However, despite this, the left hand carb is just p***ing fuel everywhere.
I ended up taking the tank off and draining the entire thing into a jerry can as even the tank petcock wasn't working properly, it was still letting a consistent dribble of fuel out the bottom of it.

I've got new fuel hoses on order as the old ones have turned to cheese and snapped off at the hose clamps without much persuasion.

I know the carb needs fixing, but I want to get the bike into a state where I can actually ride it to a mechanic if that's what it needs. I'm hoping I can just unstick the valve once I can avoid being covered in petrol non-stop.

Is there much point trying to fix the existing petcock, there seems to be a fairly easy way to make it manual in the meantime too.

Secondly, should the tank petcock still dribble, or is it likely the seal is failing in that too?

Thirdly, if the float isn't working properly, what are my best options that aren't tearing down the carb just yet?

[chris-red]

We need a sticky in this forum - GS500 fuel taps are fucking gash.

They all seem to break.

I believe you can get repair kits.

To fix the carb your have to tear it down. Either it just needs a clean/float height set or your need new float needles.

Depending on the mileage I'd be inclined to completely rebuild them.

A freshly rebuilt set of carbs in a high mileage bike makes a world of difference.
____________________
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[FollowingGhos...]

[Rogerborg]

[chris-red]

[FollowingGhos...]

So, quick update:

I pulled the petcock off, stripped it down and it was filled with white crusty gunge and I could quite easily blow through it. Cleaned it out with carb cleaner, left it to dry and put it back together.

Now takes considerable effort to blow through, which makes me think it should be much better at stopping fuel from getting through.

Just to wait for the fuel lines to arrive now so I can sort out the float valve.

[Nipedley]

The hardest part of cleaning the GS500 carbs is:

Getting the tank off
Getting the airbox back on

Everything else is easy as pie, assuming you have the correct screwdriver bits for the screws holding your float bowls on.

Your tank petcock should definitely be sealing when set 'off'. And the frame petcock should be blocked through when there is no vacuum, unless you've got it set to prime.
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CBR600 (1988) | GS500 (1989)

[FollowingGhos...]

Quick update to this:

New tank petcock is on and sealing as it should
New frame petcock arrived today and is sealing as it should

New float gaskets for the carbs are on the way and hopefully arrive tomorrow. it seems that fiddling around with it has unstuck whatever had jammed up the sticking float as it's now sealing properly.

[Chris45]

[FollowingGhos...]

So, another update to this:

Put the carbs back together with new float gaskets, put the bike back together and it was pissing out fuel, however the new petcock is stopping that when it's not running.

So had the carbs off a second time, replaced the float needle on both of them and re-seated the new gaskets, hooked it up to the tank directly in the back yard and neither were leaking so I'm going to hazard to say it might be fixed. Both were holding fuel and refilling the bowls

Hopefully I'll be able to get it all back together in the morning and the bike running.

Cheers for all the input so far

[FollowingGhos...]

Another update: finally.

The weather being as it was put me off doing anything with the bike.

The new petcock is doing it's job, the fuel tank petcock has a very slight dribble when the bike is off, so will need replacing again, or fiddling with to fix it.

I've had it out for a couple of rides and it seems to pull well. There's a little hesitation but I'll take it out for a longer run later to see if that sorts it.

Thanks all for the help though