For LZScout:
I made sure that mags were in fact on for the startup and that mixture was set properly. It's still having the same issue with start up.
For stans:
When I started the plane up I was almost certain that fuel selectors were configured properly, I can always go back and double check. On the other hand, I didn't know that the default plane for startup could affect add-on planes. If the "default flight" plane you're talking about is the one that loads in upon firing up FSX, then mine is the Trike Ultralight, which may explain the engine complication. I'll swap it to the 172 to see if that fixes anything. If it does the trick, then Thank You! If it doesn't, then it looks like I'm stuck at square one.
Thanks for the Help so far!