Welcome aboard!!
First, you will need this. It does not cover the Spectre, but the LTD is almost identical ---
www.kzrider.com/modules/ServiceManuals/KZ750E1&H1.pdf
Here are some parts diagrams--
www.partzilla.com/catalog/kawasaki/motor...983/spectre-kz750-n2
Here are some pics that might be helpful.
www.bikesrestored.com/3000/kawasaki-kz750-spectre-1983/
Some basic metric tools and some JIS screwdrivers, or suitabley modified Phillips screwdrivers, will get you started.
If it will start and run, a compression check, or even better, a leak down test, will help you determine the basic health of the rings and valves.
If that works out ok, then perform ALL of the routine maintenance. That will eliminate a host of problems, and will greatly reduce the possible solutions to any remaining problems.
You may need to replace a lot of rubber parts, like carb holders, air box to carb boots, o-rings and such, that have deteriorated over the years. If the tires are more than 5 years old, or are showing a lot of surface cracks, replace them
Post lots of pictures and ask many questions.
