NGK recommend NGK CR9E with a gap of 0.7mm (alternatively use NGK CR9EIX - iridium electrode for better spark)
The proper spark plug gap for a 1987 Kawasaki 250 is .023 to .027. Most new spark plugs come in the package already measured to the right gap.
see kawasaki . com head is under specs
12
you can go to kawasaki.com and click on my kawasaki and you should be able to get all specs needed
what about a 08 sxr 800
14 air side, 23 exhaust side
In the Kawasaki KLF 300 Service manual.
if it is diesel engine 25 foot pounds
.060
spark plug gap for polaris 425
Intake is .13-.18mm Exhaust is .18-.23mm
check specs