318 will not start

Random thoughts
Compression
Fuel
Spark

Compression.......any idea how much? Might want to run a compression / leak down test. Might want to ponder "is the timing chain slipped" Has the thing been sitting a lot? Maybe the rings have lost compression, and over-priming with fuel has 'washed the cylinders' lowering compression

Fuel......make sure it's fresh, make sure the plugs are decent and not fuel fouled. Don't be afraid to dump some down the throat....known fresh, that is

Spark.....good spark and at the right time. Just how good IS the spark? Rig a gap/ tester out of the coil, using a solid core wire. Rig it so you can see the gap through the hood gap, and crank it using the key, not by jumpering the start relay. Also does it crank good and "zippy?" How is battery condition? You should get nice snappy blue spark at least 3/8" and typically 1/2"

Might check the timing. You can do that on the starter as well.