I can't get any spark plug socket to fit my 1986 ninja 1000?

Looks like 0.7mm which seems far too narrow to me!

https://bikerrated.com/gear/maintenance/kawasaki-spark-plug-fitment-chart/

GPZ 900 Service Manual doesn't mention it

https://www.manualslib.com/manual/1425138/Kawasaki-Zx900-A-Gpz900r-1984.html?page=25#manual

650 is .032 (32 thou) or 0.9mm

https://www.manualslib.com/manual/824343/Kawasaki-Ninja-650.html?page=110

..

Yes, there are specific sockets for spark plugs, usually a deep socket with a rubber insert to stop the plug dropping out. For the ZX bikes you'll need a 'thin walled' type. eBay does them as a set for a sensible price.

you will find the thermostat located under the tank, be carful of a sending unit wire attached.

see my tips on finding a manual on google

The problem with changing some motorcycle spark plugs is getting a socket to them--once you're able to slip a socket on the plugs, you can usually get an extension into it and a ratchet onto that. However, if you can't get at your spark plugs with a deep socket and regular extension, you might want to get a so-called "wobble extension" that lets you pivot something like 10-15 degrees while still having a solid connection to socket and to ratchet. I have used my 3" wobble extension quite a bit when dealing with motorcycle spark plugs that are deeply recessed. That set-up usually lets me get the socket and extension into the spark plug well in one piece, rather than dropping in a socket and fishing around with an extension to connect it up.

try a 13/16 socket with a 3" extension

you will have to remove the seat and tank to get to them. you will need either the tool kit out of your bike or a thin walled 18mm deep socket.

Probably a gas delivery problem to the carbs. Check the lines and check for a filter in the line or at the carbs. Something is stopped up and it can't get enough gas to go any rpms.

Get a different engine just like the one you had. Google " motorcycle salvage Kawasaki " and you can probably find the engine you need there. The best thing is now you have a whole lot of spare parts > the old engine.

Please rate this answer. Thanks Andre!