Here are some plugs that will work with your KX100...
Stock - R6252K-105
BR8EIX/BR9EIX/BR10EIX
BR9ES/BR8ES
BR9EG
BR9EYA
Hope this helps.
Kevin
In the head.
100 hp searay
100-120K miles.
Every 100 000km
Spark plugs don't really burn out, they foul out. A spark plug is used to ignite the fuel/air mixture squirted into the cylinder by the fuel injector. The plug sends a spark and boom small explosion. However gasoline is not 100% clean, so it leaves carbon deposits on the plug. Over time these deposits foul the plug.
The engine seemed to be missing/chugging when we hit around 80 - 100 km per hour and the engine light came on. This is a huge sign that you need to change your spark plugs and any bad coils.
You can get the float valve assembly for your Kawasaki KE 100 on Ebay.
the spark plugs probably need to bee changed, happened to me and mine, cost about $100
http://www.ford-trucks.com/article/idx/0/100/article/How_To_Change_Spark_Plugs_on_46__54_Liter_F150s.html
The following spark plugs are specified for a 1990-1999 Yamaha RT-100: NGK B7ES (or if you want to upgrade to iridium, BR7EIX) Denso W22ES-U (for the iridium version, IW22) FYI, the spark plug gap is .022"
about 70mph
Look in the required maintenance booklet that came with the vehicle. Probably 90 or 100 thousand miles.