There is a constant drip from the drain hose. I have removed the hose from the rear of the tank and it's definitely coming from there. Drips when tank is only two thirds full. I can only put it down to a failure of the drain pipe inside the tank. This was an issue with early zx12s and a recall was made. Does anybody know the fix? It's a 2007 model with only 7000 kms on the clock.

I don't think i can be of much help but is the drip coming from the nipple on the back of the tank or is dripping out of the end of the hose like it should if there was an over flow?

How much is coming out? If you catch the drip, will it amount to much overnight? ...or just a wet residue?

I have heard of the overflow hose getting clogged with some OEM gook they put in there. Mine discharged a snotlike glob after filling up after a 4 hour ride in hot weather. If it's not a severe drip that draws your tank down over night, I'd suspect it is just clogged and will clear itself eventually. If it's profuse, I'd say there is a problem with the overflow system. Sorry, IDK eaxctly how that works but seems to me there could be a crack that lets gas in at 2/3 full level. The only openings should be up at the gas cap and down at the back of the tank at the nipple. Just my thoughts, hope you gat some more informed insight on this.

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Thanks Rook. I removed the hose from the drain at the rear of tank and the gas comes from there. I have just now put a tube on it which leads to a jar. I'll see how much comes out over night.

I think Rook is asking if it's coming from inside or outside the tube. If it's running down the outside, maybe a cracked tank/seal. Down the inside, a failed drain. Hard to run all the way down the tube on the outside, but anything is possible.

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Yeah that's what I was wondering, does the gas run THROUGH the tube?...or leak down the outside of the tube from the nipple?

It's not unusual for a small amount of gas to come out of the nipple when you remove the tube...but if it just keeps leaking from there, there must be some kind of crack letting it out. I guess that would be a fire hazard if it is leaking down the outside of the tube cuz it might be leaking on the motor too.

Hope you have Memorial Day off to check it out. Talk to ya Monday.

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I removed the hose from the drain at the rear of tank and the gas comes from there. I have just now put a tube on it which leads to a jar. I'll see how much comes out over night.

Bummer. I think they tack weld the hose inside the tank. So say the pipe wall has a pore of a hole at that melted away material somewhere? It also says 2 vent tubes only and one is for the gas cap mount and how rain or washing the bike would fill that pocket at the gas cap so that is that drain hole.

This is where you have about 3 options:
1. Change tanks.
2. Run thin medical hose small enough to run up the vent pipe, close off the vent nipple with the medical hose sticking out past the vent tube.
3. Cap off the vent nipple, run an aftmrk spin off gas cap, where you keep the tank, close the vent tube and have a gas cap with the vent built in.

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Trying to send reply but getting error message

Thanks for your input guys. I've typed this out twice so far but it wouldn't send. I've got a cup of fuel in the jar after 16 hours so the internal pipe must be leaking. I like the suggestion from Hub re running a small hose within the drain pipe but don't know what materials can resist constant immersion in fuel and is small enough to fit. The drain tube is also there to remove rainwater from the cap area and a tube fitted within would need to be sealed at both ends so that water wouldn't enter the tank. Paint or resin or locktite poured down the pipe might work?

Not a good idea. Open gas cap. Note the hole to the left of the filler hole that is recessed deeper in the tank. Clog that and water empties into the gas tank with a simple lift of the cap.

So you don't want to clog a hole on that left tube at either end. That remains open just for that reason is how that cap assembly fits on a tank. See that idea right down the drain? Forget that idea on the weather "vent." Forget washing the bike too.

Again, we have come full circle more or less.

A. A new tank is still the option.
B. The hose up the vent tube and piggy the 14.7 was more a demonstration about vent-vent-vent.
C. The only out is an old style type lawnmower cap that is one hole and the air moves both ways.

If I were to test the OE gas cap, I'd plug up the right vent with a gas resistant rubber nipple plug from NAPA or a boat store, something made for gas/marine grade type rubber, etc.

This is the scary part so either the bike feels sluggish, or the tank implodes you do not top it off first. Harder to squeeze liquid than air, right? That's the quick test.

Then step to scary part two. What happens you drain the tank and not a thing happened as if normal was the ride with full power at the throttle, etc. Now, sit the bike in the hot sun with about a gallon of gas in it. If the OEM tank cap flaps that diaphragm like blowing into a rolled up paper party noise maker, you lucky dog you; was one rubber baby buggy nipple bumper upper and over the vent tube is problem solved. Not how I'd approach it, but you are on your own with the decisions you make.

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The problem is you don't know the extent of the damage, and any "fix" would be temporary. A little more corrosion, and you could be a fireball. Used tanks are less than $200.

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