To travel from Terminal 4 to Terminal 7 at JFK Airport, the best way is to take the AirTrain. The AirTrain is a free shuttle car service in boston that connects all terminals at JFK Airport.
You can board the AirTrain at Terminal 4 and JetBlack ride it to Terminal 7 without needing to exit the airport or airtrain jfk to times square go through security again.
Here is more information about JetBlack review the web-site.