Smell of fuel in the exhaust, and carbon on the plugs (How do I lean it out?)

If I am running way too rich, then how can I solve the problem and adjust the carbs to run less fuel.

I have a strong smell of gas coming out of the tail pipes.

Do I need a new coil and wires?

What screws on the carbs will affect the mix and reduce the amount of gas?

Any write ups on this......

78 KZ 650B2 with vaccume petcock and stock carbs.

How do you adjust the carbs guys, someone must have an idea.?

I'm not an expert by any means, but have you tried replacing the carb jets?

Are you running stock exhaust and intake? Indicating that is a big determiner on getting good, correct advice.
Have you changed anything recently? Before noticing the issue? What jetting are you running currently?

As far as your coils, how much voltage are you getting to the coils? A lot of the time voltage drops with the age of our bikes. There's been several write ups done about a coil power relay mod (commonly called the Wired George Coil Mod). Search for that here, or look on his website for a detailed write up about how to do that.

If you do need to lean out your jetting you'll have to determine if it's the pilot circuit, the needle circuit, or the main circuit that needs to be leaned out. The pilot and main jets are under the float bowls and the needles are adjusted by through the top covers.

Here is a link to a lot of great information about tuning on our 650s. maintenance.kz650.info/GeneralMaintGuides.htm

Follow the last post's links. Also, if in fact you are rinning rich, you either need to add more air to the mixture or less gas.
Using anything but the stock air box and exhuast and the carb jets may need to be changed to reflect the new air/fuel mixture.

If the bike is stock I would think it would have stock jets, did this problem just kinda start? Has it always been like this? I see you've had the bike since 2007, always been this way or did it start after you did something to it? You may just have crud in your carbs and possibly causing stuck floats? Let us know...

The bike is stock everything, except the K&N filter.

I found a huge hole in the left side exhaust and patched it up yesterday.

I hope that it holds until the winter until I put on a new exhaust.

The spark at the plugs is it a good strong ark or a bunch of little sparks. After compleating the relay mod mentioned before. check the resistance on the coils 3-4 ohms input and 23,000 on the output without the caps, while you have them off clip 1/4 off the wires to make a good contact.
I was having basically the same problem your having, I found coils to 1&4 to have a output resistance of 50,000 ohms, put on a new coil and it runs and idles better than ever did.