Don't know if this is helpful or not but I work at a library on a 2-year college campus that has a recreational engines program. We have a bunch of books including manuals for KZ's in our library. We also have alot of books on building perfomance engines, restoring older bikes, engineering theory of chassis, 4 and 2 stroke engines, electronics, carburation, body work, welding, painting, and almost everything else you could want. We also run a program called I.L.L. or interlibrary loan. If a patron of any library in the state wants one of our books then all they do is request and we send it to that library.
It's quite possible that what ever state you live in they have a similar program as our I.L.L. They should also have a database of all the books for easy searching. If your looking for engine or chassis theory for racing I suggest John Robinson's Motorcycle theory books. They are pretty good and include tons of things like formulas to calculate almost anything motorcycle related and how to write some pretty wicked BASIC2 programs that will give good information on lots of things.