You forgot fuel make sure you have fuel pumping to carb or injectors which ever you have.
The engine needs fuel, compression and spark to run, it is missing one of those.
Check engine compression Check engine timing
engine cranks but wont start means one of these things.. Air, Fuel, Spark, or compression
No, The compression test is done as the starter cranks the engine
The engine needs fuel, compression and spark to run. You are missing one of those. Year, make, model and engine size would help us help you.
An engine which cranks but will not start is not receiving enough fuel or has no spark. A clogged fuel filter or bad spark plugs often cause this problem.
Does it have: fuel, spark, compression?
No. It should start. It may run poorly and lack performance but it will start. If you have a no-start condition, (starter cranks over engine but engine doesn't start) check for spark, fuel and compression. You are missing one of these.
Does it have fuel, spark, compression?
Does it have fuel? spark? compression?
For some reason it is not getting EITHER fuel OR spark , so it cranks but doesn't start
Engine needs fuel, compression and spark. You are missing one or more of those.