Try spraying carb cleaner or starting fluid in the air filter. See if it wants to start. If it does it is most likely a fuel issue. If you are positive you have spark then do a compression check. Make sure your new motor is actually good to go.
Earlier I was helping someone on this forum that said they had spark then later told me they changed the coil and that fixed the problem which tells me they didn't really have spark, so check at the plugs to see if you have spark.
It sounds like you are pretty confident that you have fuel because your pressure seems right on, but make sure you have spark at all of your plugs. Double check the cap for moisture or carbon tracks. Make sure the coil wire is pushed all of the way in and on the coil.
Pull the spark plugs and lay them out in order that you pull them in case one is a different color that could tell you that you are having an issue with that cylinder. Say all are white but one is dark, that could tell you you have a problem in that cylinder. Also can could be more than one cylinder.
Keep us posted and if you do fix it, let us know what the issue was.