Kz1100 running very rich

1982 kz1100 with bs34's. The other day I went for a ride with my son and the bike would act up at a steady speed and even at an idle but when I was going through the gears it seemed to run ok. My son riding behind me complained of black smoke that even made him sick. I believe that while I was running a steady speed vacuum was pulling gas in but when I would go through the gears vacuum would drop and not suck gas in. The bike has the vacuum operated fuel valve and that's where I think the gas is being sucked in. but I'm also wondering if maybe the diaphragm on top of the carbs could be the problem. I don't know much about these carbs. And if it could even suck gas there.
Eddie

If I was running that rich,my initial suspicion would be flooding of the carbs due to the floats sticking or similar. The other possibility is the fuel enrichment circuit for cold starting leaking fuel because it's not sealing when the "choke" is off. How does the bike idle when warm?

The clear tube test may help determine whether the fuel level is too high.

A leaking float valve (for whatever reason) can allow fuel level to rise and result in an over-rich condition.
In extreme cases, the fuel may rise high enough to allow raw fuel into the carb bore which is then sucked into the combustion chamber.

To be on the safe side, would sniff-test and physically examine the crankcase oil to check for fuel contamination in the crankcase.

Good Fortune!

redhawk4 wrote: If I was running that rich,my initial suspicion would be flooding of the carbs due to the floats sticking or similar. The other possibility is the fuel enrichment circuit for cold starting leaking fuel because it's not sealing when the "choke" is off. How does the bike idle when warm?

It would not idle right at all
I ran it about 60 miles and the only time it would run clean is when I was getting on it.

Patton wrote: The clear tube test may help determine whether the fuel level is too high.

A leaking float valve (for whatever reason) can allow fuel level to rise and result in an over-rich condition.
In extreme cases, the fuel may rise high enough to allow raw fuel into the carb bore which is then sucked into the combustion chamber.

To be on the safe side, would sniff-test and physically examine the crankcase oil to check for fuel contamination in the crankcase.

Good Fortune!

The oil was loaded with gas.
I have not ran it since that day, when I got i home I dumped the oil and pulled the clutch which is was burnt up I,m not sure if the gas caused it as I was having trouble with it before

As another poster suggested, put bike on center stand and check float level using clear tube method. I would also guess that you have a float stuck or dirt in needle and seat causing fuel to keep pouring in.

I'm gonna try that

Are you sure the clutch is burned up? A mis adjusted cable or a gummed up release mechanism can create similar symptoms.

If you disconnect the vacuum tube from the petcock while it is in the run position or the RES, does gas still run? Sounds like fuel is just running into the engine before the carb.
Steve

Would also assure that no gasoline is coming from the petcock vac nipple.

Good Fortune!

TexasKZ wrote: Are you sure the clutch is burned up? A mis adjusted cable or a gummed up release mechanism can create similar symptoms.

Its defiantly burnt and I thought I had a clutch problem before the gas problem but the more I look at it, it loaded the crankcase with gas and I kept riding when I should have turned to home. makes me feel like a dumb ass.

Ok here's what I did I put my vacuum gun on the vacuum port on the valve. I had just a trickle of gas come out the vacuum port but I have the oil drain plug still out and gas flowed from there and even had gas leaking into the airbox I believe its coming from the outside carbs. I took the airbox boots to carbs off and am going to put vacuum on it again and see for sure which carb or carbs are leaking.
with as much gas that is coming out I can't believe it even ran.
And I'm sure I burnt the clutch up cause I'm stupid and kept riding.