Another question about gas overflow issues

I have a Kawasaki 1982 KZ1000 K2 LDT.
I purchase 4 carburetor rebuild kits Part number (KL18-2436).

My problem is that even after replacing the Float Needle Valve Seat assembly it is still leaking gas. Granted it's only 1 drop every 30 seconds to a minute, but this is enough to overflow the carb when it's seating long enough.

I have cleaned and recleaned this carb. I have inspected the chamber the Float valve is inserted in. I have the gas going thru a brand new filter. I have blown out the float value with air and made sure there was no dirt or varnish messing with the float needles. However when I take the bowls off and hold the floats up I still have two carbs that are leaking gas from what looks like the needles themselves. Is it possible I got some needles which are defective? What do you suggest?

Chris
Richmond, Va

Are you saying that it is overflowing while the bike is running? If it is, then possibly you need to set the float levels.

I have the carb on my work bench and I'm just using a tube and funnel which holds about a pint of gas, enought to fill the carbs and have a little still in holding. Then I just let it sit. Around 1 hours my carb will be overflowing. I took the bowl off and then put a wedge under the float to hold it up. It looks like the gas is leaking around the needle.
My float level is correct, but give it an hour or so and then it over flows. After replacing the needles and needle seat I fixed one carb, but ended up with another two that leak now. It leaks from what looks like the needle. Like I said I wedge the float up and still get a slow drip. I have held my finger over the needle seat (after removing the float and needle) and I don't seem to be getting a leak, but it's hard to sit there any length of time and not move my finger.

On my carbs the needle seats don't use threads. Its held by the o-ring on the outside of the needle seat.

The previous owner allowed the gas to go to varnish. The motorcycle runs, but was leaking gas when it sat.

Just curious. Any chance my tube and funnel might be creating too much gas pressure?

I was just thinking about this tonight. How much pressure is the fuel tap suppose to allow? Or is this a straight thru system meaning that the fuel tap does not control pressure, which if so then why does it have a spring and diaphragm plate?

I looked in my manuel and it does not mention anything about troubleshooting if there is a problem in this part of the fuel system.

By the way this is the orginial CV carbs. So it's not fuel injected.

Post edited by: snowkloud, at: 2006/04/25 21:44

Just to clarify...is this symptom happening when you have the carbs on or off the bike? From your description it sounds like you're doing a bench test, with the carbs removed. I'm no guru like some of the other guys here, but I thought that the reason you need to turn the gas off when the bike is parked is to keep fuel from flowing into the carbs when the bike is not running, causing the carbs to overflow. If the carbs are not pulling any gas into the combustion chambers it seems like they have no option but to leak it through the overflows, even if the floats are set correctly. Hopefully one of the many carb gurus here will chime in and confirm or deny this.

I just did a repair on a friends Honda (I know, friends don't let friends ride Hondas)and he had the same chronic leaking problem. It turned out that the brass overflow tube in the float bowl had a crack in it and it allowed gas to seep directly into the overflow tube with barely any fuel in the bowl. I fluxed it and soldered it and the repair has held very well. You might want to pull your bowls and inspect your tubes VERY carefully. Brightening the tubes with 0000 steel wool might help to find the culprit if you have a crack.

The carbs leak on the bench as well as on the "non running" bike on the center stand.

Brass tubes are good. The gas just seems to be leaking right around the float needle even the brand new ones (valve and needle). I checked inside the float valve seat and checked the needle for dirt or such. Both the old set and new are clean. I ended up putting the old ones back in for carb 3 & 4 with new o-rings because they leaked the least when compared to the new ones.

As it stands now I have carb 1 & 2 with new float valve and float needle. Carb 3 & 4 with old ones, but new o-rings. Of that I still have carb 2 and carb 4 dripping. (On bench) When I pull the bowls off and wedge the float up both look like the gas is coming right around the float needle.

I'm in the same boat.

I just rebuilt the 4 mikuni's on my 78 KZ650B and number two has started leaking after 5 days on the bike with fuel on it.

Has not been drive, but the overflow starter after running the machine and playing with idle air ect.

Took bowl of and looked for dirt, lowered float a wee bit, better but still some drips.

Idea's??

Thanks!

-Ian

If the leak occurs with the bike running, the float level is not set correctly or the overflow tube is cracked. If the carb leaks with the bike parked, you forgot to turn off the gas. ALL needles/seats will leak if the gas supply is left on. They are crude and not intended to be a super positive gas shut off. That would be what the OFF position on your petock is for.

I fixed my leak. The guys (Jeff and Steve) at Z1 Enterprises went above and beyond to discuss my problem and helped get me replacement float value and needles. Well I replaced the new ones with the ones Z1 Enterprises sent me last night and my problem was solved. Guess the ones that came with my carb rebuild kit were bad or damaged somehow that I could not physically see.


Wiredgeorge,
My petcock only has a On, PRI, and Res setting. I'm guessing since mine is a vacuum petcock that I don't need an "Off" setting.

1982 Kawasaki, KZ1000 K2 LDT

If you have a vacuum actuated petcock and gas leaks when the bike is shut off, the diaphragm isn't doing its job. NO seats/needles will keep gas from leaking positively. Fix the petcock so that gas stops flowing as intended by the manufacturer. Eventually, your new needles/seats will leak if gas is getting by when the bike is parked.

Ok, I'll buy that nothing will work perfectly.

What would be a good source for a rebuild kit for the vacuum petcock on the KZ, or a replacement one that will postively shut of the fuel?

Thanks!

-Ian