gas dripping from overflow tube

sounds like you have either a faulty needle valve or some dirt in the needle valve, or possibly your float level could be set a little high , it realy all depends on whitch breather the fuel is coming out of,

I agree too.

Everything you need to know is right here... start wrenching.

http://www.dirtrider.net/justkdx/

See "Carb Float Level" and "Carb Tuning" under the KDX Tech Tips section.

Check the pin that holds the float to the Fuel Valve. You have to take the carby apart. It happened to me once and the pin came out, thus allowing the float to float and the fuel valve to piss gas.

What about when the bike is not running. Is a small amount of leakage (after turning the petcock off) overnight normal? I know it's to be expected if you forget to turn off the petcock.

I've been working on the bike a fair bit lately, idling it on the side stand. Turn off the petcock each time before pushing it into the garage. Next morning, small puddle of gas under the overflow tube.

check the needle and seat that the float pushes up into place, also check if your float has a crack in it. both of these are common problems with carburators.
good luck.

I would remove the carby from the bike, its not a hard job then remove bowl and just check the points mentioned earlier, my kdx dropped about 2 litres of gas on the garage floor the other week , and i replaced the needle valve problem solved, another very rare problem that can occur is if the float assembly ruptures, and fills with petrol, it will always be heavy and never rise fully so shut off needle valve, this is not likely to be problem, but i have seen it once before.

crazybrit said:

What about when the bike is not running. Is a small amount of leakage (after turning the petcock off) overnight normal? I know it's to be expected if you forget to turn off the petcock.

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To answer your question: This is fairly normal. In most cases it's a matter of the KDX petcock being pretty picky about what 'off' is. Just a tad off 'dead-center off' and it will leak.

The other points do apply to leaking fuel..but don't address the petcock part.

Related to hard starting?

canyncarvr said:

To answer your question: This is fairly normal. In most cases it's a matter of the KDX petcock being pretty picky about what 'off' is. Just a tad off 'dead-center off' and it will leak.

CC:

The other points do apply to leaking fuel..but don't address the petcock part.

Click to expand...

Interesting as it seems to be doing it more of late. Not suggesting for a moment that the above is incorrect however.

The first time I first noticed it was after I'd put the bike back together after it had been down for a few weeks (waiting on parts/bearings to arrive). Started to get some fuel on the floor next day with the petcock closed.

Also around same time started to have some starting issues.

Couldn't start it. Nothing. Pulled the plug (B8ES) and it was heavily carbonized on the electrode. Cleaned it with a wire brush. Started first time. I'd been running it on the side stand a fair bit and hadn't ridden in in ~6 weeks so I didn't think more about it. Figured I'd see how it ran on the trails, but then wasn't able to actually get out and ride :(

Yesterday Devol rad guards finally arrived and I had to pull off the left rad to reshape it (from when I dented it last ride). Got it all back together and it stubbornly refused to start. Not even a splutter. Only gas leaking out of the overflow tube when I was kicking.

Pulled plug, cleaned it, no change. Checked plug, had spark and plug would be slightly gas-wet when I pulled it.

Went and got a fresh BR8ES plug. No diff. Drained float bowl.
Kicked it. No change. Drained float bowl again. Gas looked ok. Checked plug, gas is getting there. About to despair when it starts up.

Seems to be restarting ok now, ~3 hours later, stated first time and restarts when warm fine too.

Carb issue? Normally these always end up being weak spark/ignition issues (at least on previous bikes). Or ignore for the moment and get out and ride the damn thing?