It is a F9 Bighorn 350cc - This was the first 'big' bore trailbike that Kawasaki ever made. It is a rotary-valve 2-stroke single. These made about 35hp standard, but can be easily modified to belt out between 45-50hp....
That front-end is what is known as a 'Hatta' fork - the front axle can be placed in 1 of 3 positions - either leading axle (in front of the forks), centre axle (in line with forks), or trailing axle (behind forks) - this was to achieve a range of handling options, depending on the type of riding being done.
I really only wanted the motor, for another weird project, but because this rig has so many good original parts still on it, I guess it will become a restoration back to fully stock. There are enough spare engine parts to build another motor for my other project anyway, so its worked out pretty well.....
Should be good for the Pre-73 MX class in vintage MX eh ??
...I've got a few more things to check this weekend, but if I still have no luck I might bring it over anyway and get you to have a ride. I think it's been caused by a combination of problems that I just have to keep chipping away at 
