88 Kawasaki ninja ex 500 wont start?

You need to start with the three basics fuel spark compression if you have all three it will run in the case of spark it could show spark when ur testing it but under cylinder compression it could be weak fuel is easy take carbs off spray fuel in intakes and crank if carb or fuel is an issue then it will start compression is easily checked take plugs out and crank with hand close to plug hole if air pushes past u have some sort of compression the best way is to use a compression tester or cylinder leak down Gage to pinpoint the loss of comression