Hello!

Picked up a 76 KZ400 S2 just yesterday. My first motorcycle in about 6 years and my very first Kawasaki.
In a previous life, I lived in the UK and rode a Suzuki Bandit 600 pretty much every day. Events have brought me to New England in the US and I've found myself itching to get back into bikes.
I learned a tonne tinkering around on the bandit but I always wanted to delve deeper into the engine and I've wanted to take on a restoration project for a very long time.

This bike is definitely going to be a project. First things first I need to check the fundamentals and figure out if the engine will run. If that works then both wheels have significant rust damage and need replaced. It definitely needs new forks and possibly a new swingarm. It's gonna be fun!
The previous owner said it had been sitting in a barn for the past twenty years. He couldn't find the key but he did have the original title from 1976/77 which I found pretty amusing.
I enjoy restoring vintage tools and putting them back to work so I will be chuffed if I can get this thing back in working order.

I love finding these communities and delving into all the collective knowledge and experience. Hopefully I'll be able to contribute a little something here and there too!

Looks like some good bones to start with. 
Welcome to our group. Thanks for the pics. We love pics. Please keep us informed of your progress.

Welcome aboard! Thanks for saving another one from the scrap heap.

Welcome from another Englishman 

Welcome. You have a quite a project on your hands but when you are done... the KZ400 is a fun bike to ride. You have a front drum brake, so you won't have to deal with the unobtanium front caliper seal. 
For the missing key, locate the number on the lock and then contact the member here who makes keys or hit up eBay. 

Thank you. It'll take me some time but I'm ok with that.

Thanks for the tip, I've contacted the member here and should be on my way to sorting out a key. One step at a time right!

Welcome to KZR!
I will have your key made and sent tomorrow.
By the looks of your bike, I suggest some lubrication in the keyholes.
Silcone Lube works well, or any lube you may be able to get into the keyhole.
WD40 dries fairly quick, but can work to start.

Thanks so much! When I brought it home I really expected the no key thing to be a much bigger headache. Really appreciate your skills and willingness to offer assistance.
Thanks for the tip on silicone lubricant, I'll pick some up tomorrow. The keyholes are the first in a long queue of things that need some lubricant...

I did have the pleasure of clearing out an abandoned mouse nest behind the side panel when I was chasing down the key code. Quite an adventure.