Tach cable drive leak

77 KZ650B
Noticed a leak where the Tach drive gear assembly exits the head. I removed the locking bracket that holds the hex headed assembly in place. I looked up the Kawasaki part and ordered a new O-ring (I'm assuming the culprit) .
My question is how does the hex head assembly get removed ? now that the locking bracket is off, does it thread out or does it just need a good pull to remove??
Thanks

It just pulls out, but may be stuck and need some effort, and sometimes no effort will budge it. Also be sure a gasket is in place between the cable and the drive. A simple flat washer shape gasket. Some parts list show this part, some do not, but it's needed to keep from leaking and is always lost first time the tach cable is replaced, which on a 1977 is about 1979. Make your own out of thin cardboard or gasket material, or it's still available from Kawasaki. My drive was hopelessly seized to the head on my KZ1000 nearly 30yrs back and the leaks were all fixed by adding the missing flat gasket. I never to this day got the drive to budge out of the head.

Thank you for the tip regarding the cardboard gasket at the cable connection (of course upon inspection was missing and certainly could be a contributor to the leak / seepage ) Fortunately the drive unit came out with a good tug.. I've got an new o-ring on the way and made a gasket for the cable connection out of gasket material,,, that should get me all fixed up.
Thanks again for the info!

The tachometer drive has a gasket, oil seal & o-ring. A fiber washer might work as a suitable alternative for the gasket.
I'm not sure if Z1Enterprises.com still has the tach drive kit, but they do have the oil seal.

+1 on also replacing the tach drive shaft oil seal.

The existing seal is likely an old hard worn-out leaking encrusted fossilized chunk of carbon.

Some patient work with a dental pick type tool will extract all remnants of the old seaL

With properly functioning o'ring and shaft seal, you can ride cross-country without any tach cable at all and not have any oil excaping around or through the tach drive.

Good Fortune!

Great,
yes I was overlooking the seal, and yes hard as a rock! Ordered one from Z1 , Hopefully my three point attack, o-ring, seal , and gasket, should keep here sealed up for another 41 years.
Thanks for the info !!!!!