check the tubes and see if they are in good condition

i had a very similar problem, with consequences that looked very similar

and it turned out to be that a tube had rotted and had holes in it

 

Which tube? I'll check them all, but which one failed for you? The main fuel line, the vacuum line from the carb to petcock, or something else?
I feel like though that if the vacuum line was leaking, the petcock wouldn't dispense fuel, and if the fuel line was leaking, the gas would come out there and not out of the overflow between the carbs.
I really think this is a pressure buildup issue, but I don't know how pressure could be building up and forcing gas into the carbs.
I'll check the lines and let you know what I find, but any other suggestions?

 

check/replace them all. if there is a problem in one line, there is a problem in all the lines. rubber installed on the same day will rot at the same rate.

 

I checked the vacuum lines... no leaks. Any other thoughts?

 

underwear gnomes, perhaps helper monkeys. set up a surviellance camera.

not vacuum lines, fuel lines.

 

You don't think it's possible that you've just plain got crud in your fuel tank that's getting into your carbs do you ?

 

hey
just got back from a prev. customers house that ownes a 1985 GPZ900 w/ the same problem you do.
tore the carbs down and lots of crud to be found but that wasnt HIS problem. his floats are made of plastic and they are old so now they have filled with fuel which in turn causes the bowl to keep filling and filling and filling and filling and filling w/ fuel so it has to go somewhere.
i would pull the carbs and make sure the needle is actually sealing in the seat (look for a small groove on the needle tip) and make sure the floats are empty and that there is no dirt down in the seat area holding the needle open.
good luck

 

I had same problem with my EX500, I eventually got a petcock repair kit and rebuilt it, that seems to have solved the problem, maybe it's just worn out and needs replacing, if you're confident of your carbs.

 

Okay, well I'm pretty confident that the carb needles aren't worn seeing as how they're new. But crud in the tank is an interesting idea, I'll look in to it.

Also, the dude with the EX500 - I have petcock issues too... every now and then it leaks. It's seems to happen mainly when I switch from off to on or reserve. What exactly was damaged in your petcock that caused it to flood the float bowls?

 

necro-BUUUUUUUUUUMP.

I'm having the same problem as the OP.
The overflow between the two carbs is dumping gas when I ride. It's not leaking any gas when it's off. The lines are all fine, no holes to be found. When the fuel lines are disconnected to the petcock and it is turned to on, no fuel dumps out. I do not believe there's a problem with the vacuum diaphragm. It's not leaking anything near the petcock as well.

When I ride, gas just starts dumping. And it will surge constantly. There's zero power, it will just not take off (don't say that the problem's that it's only a 250...) The air box also has lots of gas pooling in it after I ride as well.

I do not know what the problem is. It just started doing that. No idea why. >_<

Any help would be appreciated.

Thanks!!!!

~Zar4

 

I say this without any meanness or rancor, but, some of the vacuum operated petcocks that Kaw uses are not the pinnacle of kaw engineering, IMHO.
I switched mine out for an old school ON/OFF/RES one because, now if I have this kind of issue, I at least know that it is my carb.

 

I'm not sure what overflow you're talking about since you didn't post what bike you have. First guess would be a stuck float. Could also be trash in the float valve or a worn out valve.

 

Sorry, my bad.
It's a 95 Ninja 250.

Suppose it is a stuck float or crap stuck in the float holding it open, how would we clean it out? Just take the carbs out at go to town on them with some carb cleaner? As far as I know, you're not supposed to do that because it's bad for all the little rubber seals in there.


~Zar4

 

If something's stuck in a float valve orifice, you're gonna have to remove the carbs, take the float bowls off, remove the floats and needles, and take a q-tip to the orifices. Might as well put in new needles while you've got it apart. Make sure the floats are actually floating. If they're deteriorated, they may not float on top of the gas as they should. Put everything back together, put the carbs back on the bike and start it up. (It'll take some cranking to get the bowls re-filled, so don't worry that it doesn't start at first).

After running for a minute or two, shut down and get about a 6" length of clear tubing that fits the 'nipples' on the bottom of the float bowls. Fit it on one of the 2 nipples and open the valve with an allen wrench, while holding the tubing facing upward next to the carb. When the tubing fills with gas, it'll tell you how high the fuel level is in the bowl. It shouldn't be any higher than the mating surface between the bowl and carb body. If it's higher, your floats need to be adjusted to keep LESS fuel in the bowls.

Sorry to get so detailed....I went through this with my '94.

 

Thanks, get as detailed as possible.
I've messed with carbs before on another bike, I've just never encountered a problem like this. It just doesn't seem to make any sense as it happened out of nowhere. If it was tuned doubleplusrich, it would have been flooding out since it was last adjusted. Just one day it started surging and puking gas.

07ninja250, mind if I PM you should I need any more specific help? I'll be sure to post the solution with pics afterwards.


~Zar4

 

Did It Work

Thanks, get as detailed as possible.
I've messed with carbs before on another bike, I've just never encountered a problem like this. It just doesn't seem to make any sense as it happened out of nowhere. If it was tuned doubleplusrich, it would have been flooding out since it was last adjusted. Just one day it started surging and puking gas.

07ninja250, mind if I PM you should I need any more specific help? I'll be sure to post the solution with pics afterwards.


~Zar4

Im having the same issue did it work and did you take picture and post them

 

i have a 95 that is now doing the same flooding a solution would be great..
carbs were cleaned and rebuilt last summer and would start and run fine all winter (started and let run in my garage) now that the weather is nice and i want to ride its pukin gas...