Fuel pooling on ground

Hey guys I need a little(lot) of help. All of the sudden instead of having to pull my choke all the way open there is way too much gas in the lines when I start my bike. And now the last couple of days there has been a pool of gas under the bike after it has set for a couple of hours. What is going on? I know it has to be something in the fuel delivery between the tank and the carbs but I don't know that much about my bike yet to really figure it out.

I have a 1980 kz650f. Any help would be appreciated. I just don't want to lose all my fuel to the ground I would rather ride it out of the tank.

By the way after the bike is on it seems to run better now than it has for awhile so fuel delivery is happening in a great way it just needs to stop when the bike does.

It could be a leaky petcock or a float needle not seating properly. Can you tell where the gas is coming from?
Check you oil and see if it smells like gas.
If it's in the oil, my guess would be the float needle, and it would time to clean the carbs.

checked the oil doesn't seem to smell like gas. from what I can tell the leak is coming from the 4 breather hosed that go from the bottom of the carbs to the ground.

If it is the petcock is there a simple fix or does it have to be replaced?

Well, since I haven't mastered motorcycle diagnosis over the internet yet, I can only try to help.

Those are your overflow tubes.
It sound like you petcock is leaking and since your float needles are closing (like they are suppose to) the float bowl keep filling until it reach the top of the overflow tubes in the bowl, then it just drains out the hoses on to the ground.

I am not familar with the petcock you have, since it's a 1980 I would assume it's vaccum actuated. You can buy a new gasket kit for it, but the results I hear from those with that kind of petcock are 50/50.

Jeff at Z1Enterprises sells replacements petcocks and I think gasket kits, you can go cheap or expensive...your choice.

Post edited by: mariozappa, at: 2007/06/14 16:43

Thank you for the help. I will try that and let you know.

I appreciate it.

mariozappa wrote:

It could be a leaky petcock or a float needle not seating properly. .

sounds like it's the fuel petcock if it leaks even when the bike is parked.

but just in case it's a sticky float needle, i might add a few comments based on my experience:

- in my case, the fuel would overflow fairly quickly, and run onto the ground even when i was stopped at a red light. a few times when the light turned green, my rear tire almost spun out on my own gasoline on the asphalt.

- fortunately my sticking needle was on one of the outside carbs. i was able to remove the float bowl and clean the float needle without removing the whole 4 carb assembly from the bike.

- if it's a sticky float needle, you might add some seafoam to your gas tank. think i've read a few times that it helps unstick sticky float needles.

good luck

It sounds like you have 2 problems. Problem #1-bad vacuum petcock allowing fuel to flow when engine is not running, and problem #2-bad needle/seat in one or more carbs. You about have to have both, because if just the petcock was bad and the needle/seats were good, no gas would overflow when parked, and if needles/seat were bad and petcock was good, no gas would leak when parked either. Pull your fuel line off the petcock and see if gas gushes out. If so, bad petcock, then procede to the carbs needles/seats. Also a couple guys have had gas go into the crankcase. One was because the vacuum petcock diaphram was bad and gas went right down the vacuum line into the engine. This is always a rare possibility. That is the one and only way gas could ever go into the oil, at least on a KZ650 because the gas level would have to rise 10mm above the overflow tubes which is impossible unless the tubes are clogged and yours aren't because they are doing their job letting gas flow onto the ground, not into the engine. That's why the overflows are there.

Post edited by: RonKZ650, at: 2007/06/14 22:55