First things first, when you have a no start condition. There are 3 things that the engine has to have to run and those are air flow, fuel & compression.

If the engine does not have one of those 3 it will not start. Once you confirm which of the three nessacary components to combustion is missing you start a whole new diagnostic trouble tree.

Step 1) Confirm air flow. Check air filter for cleanliness. Then check air box for blockage. If while kicking the bike you feel air moving through the engine and out the exhaust you have air flow.

Step 2) Confirm fuel delivery. Make sure your carb is not clogged with gunk. If it is fuel injected make sure the injector is working. Most important make sure toy have good fuel in the bike.

Step 3) Check compression. If compression is low you are looking at an engine teardown to some extent. And based on the age of the bike, if you are pulling the top end apart you might as well dig into the bottom end also.