All internal combustion engines need the same things to run- - -

Fuel
Air
Spark
Compression
Valve timing
Ignition timing

Any one of these going wrong will keep it from running, or at least running "right". Never, ever "assume" things are correct- - - -until you prove beyond any doubt that something's right, you have to suspect that it's wrong. Fortunately, each one of these things has a specific method of proving it's correct. Pick one item, check it out until you're sure it's right, and move on to the next one. Don't bounce around from one system to another.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!