The owners manual for the KZ650 1977- 1983 reads as follows
"- Spark plug
Type .......... NGK B7ES, ND W22ES-U
Gap ........... 0.028-0.031 in (0.7-0.8 mm)"
www.suddco.com
3.65LTRS
The size of the rear tire for a 1978 KZ650 is "M 130/80 - 18".
First turn your gas switch off, then pull your fuel lines from ports connected to tank. then simple pour the gas into a desired container, and reconnect fuel lines.
the drain plug and filter is on the bottom of the engine, put the bike on the center stand and put a oil drain pan under the bike, remove the drain plug, remove the filter cover, remove and replace the filter, replace the drain plug and fill with 10w40 motor oil 3.7 quarts
1500
I believe they were rated at 76HP, but it could be anywhere from 75 to 85HP
no points , has electronic ignition on a 1978
Purchase a Haynes or Clymer manual or possibly download one free. Search online. Their electrical diagram are copies of genuiene Kawasaki workshop manuals.
Standard plug is NGK B8ES set gap between .028--.032 in.
My Chilton book shows that it has electronic ignition ( no points )
On a ( 1978 ) Ford 302 cubic inch V8 engine : It has Electronic Ignition , so there are no points