Hi Bill
The difference between the two engines is mostly in the carburettor. The old version (mine is from 1995) has a super tigre carb and swapping it for our current design Laser carb gave me another 2-300rpm. Clearly results will vary between engines but I was very happy with the upgrade. If your engine is 7 years old there should not be any real difference between it and the current spec engine. If you pop up a photo I can probably narrow down its age, and the year of mfr should be stamped on the mounting lug