You're a new boater as I have seen you ask many questions in this forum lately.

If I were you, I'd take the thing in to a Mercury mechanic and have them
check it out. Why run the risk of seizing the engine should the injection
system not be working?

For the peace of mind of it all, why not just have someone who knows the
engine take a look at it? You've worked too hard to get to this point.

barry