Sounds like you are over thinking this a bit.

First, you need to determine if you have an electrical problem. Loose terminals can cause sparking and can also cause the starter motor not to engage. Tighten those puppies up before you decide the problem is elsewhere.

If the starter motor is not engaging you need to check that it is getting power and that it is grounded. A bad/weak ground can cause the starter not to engage. A quick check is to run one lead of a set of jumper cables from the negative terminal of the battery to a metal spot on the block.

If the starter is engaging but the motor won't start the problem is either no spark, no fuel, or bad timing. If you have been cranking the engine with no start the plugs could be soaked with gasoline. They cannot spark under those conditions. You can pull the plugs and see if they smell of gas. If so, you are getting fuel and you need to clean up all the plugs.

If you aren't sure about "fire" take a single plug wire off, stick in a spare spark plug, lay the threads against a grounded part of the engine or engine compartment and crank the engine. You will be able to see a spark--particularly if it is dark.

Last step is timing. Unless you have messed with the timing since the last time the engine ran this is not likely to be an issue.

If you try all the suggestions in the posts without success, provide us with a detailed description of what is or isn't happening and someone will likely come up with other, better suggestions.