you are correct to wonder, as you can hurt things if the spark jumps at the wrong place or kick back voltage spikes into CDI and cause problems.
auto part stores sell spark testers that are adjustable or you can make your own. Just do some searching on the web

Is there a way to test the CDI?

you can test the inputs and the outputs of CDI to make sure they are in spec.
Need the proper testing equipment

Good Friday Evening Everyone,

I was finally able to get down to the boat to check for spark. I have good spark on all 4 cylinders and the plugs look good (using the plugs from the running engine and all plugs were installed at the same time on both engines).

So I am back to fuel delivery....I have a few things I know to try first of which will be to replace the fuel bulb again just to make sure that's not the problem, but I don't think it is.

Next in line is the in-line (engine mounted) fuel filter....it looks clear without removing it but I know that what looks good while installed can look completely different when removed and further inspected.

That leaves me with the fuel pump. As I have read, these don't often go bad, but they can....my question on this is what would the symptoms be just prior to failing and after failure. Is there a way to test to see if it's working prior to swapping?

Here's how I got here. Dad and I took the boat out for the spring shakedown run a few weeks ago. Everything ran smoothly and both engines fired up without a problem. This was after I rebuilt the carbs after the boat sat un-used for 1.5 years. After rebuilding the carbs (before firing up the boat on the hose), fuel tank (single tank feeds both engines) was drained and new fuel added and 2 new external 10 micron filters/water separators were installed.

Two weeks ago, we along with the wife and kids, went to take the boat back out. Boat started at launch with ease. It ran at the dock for ~5 minutes but suddenly stopped. I was able to fire it back up without issue and off we went. Just as we reached the no wake zone, the engine shut down again, but this time I was unable to get it to re-fire. We limped back to the launch ramp on the starboard engine (port engine raised out of the water per the manual).

We have replaced the fuel filters/separators thinking maybe there was some trash sucked up (even though the old filters didn't appear to be fouled we wanted to be 100% sure and in the scheme of things they are not that expensive). We also verified there was no water coming out of the 2 old filters that we could tell even after the fuel had set in a sealed jar overnight.

I really need help and unless absolutely required, would like to fix this myself to save money.

Thanks for any help anyone can provide,

fuel pumps are maint items, they fail.
if the spark is good fix the fuel system.