sweet gun!
Hey Fred, don't feel bad or get a small guy complex over an Explorer. A lot of us, and my favorite spear-type guy included, started out with one, and I still have and use it! The length of it and the single/double band setup are simplicity itself and will get you on the program with a minimum of futzing with it.
My favorite rock gun to this day is the slightly bigger version of the same gun, it was called the 4G32, with all the improvements that a lot of years and error help develop.
One thing I'd look at doing first off is to reduce the amount of line that holds the shaft to the gun from two wraps to one. Even if you get more than the usual freshwater viz of, what, 3-4 feet?, the bands and the accuracy of that gun will dictate that you get pretty close to that carp, and don't kid yourself, carp are extremely wary. And they fight like bulldogs on speed. Some guy's I know that do a lot of fresh 02 hunting, go with a three prong tip to aid in snap shots where the thing is about to bolt. Out here in salty land, you can maybe wait it out and see if it comes back to investigate, but you see a carp get ready to bail, nail it! Even if you end up just winging it, you'll still do the water a big favor by killing that trash. When I was a kid, I'd get a dollar apiece for 'em before the summer season at a local resort on the River.
Good luck.
sven