1997 GTX lacks throttle response

[papamama]

Hey folks, 1997 GTX wont pass 4000 rpm....had it to a "Tech" guy....for tuning.....two years later we got it back, starts fine, decent idle but super slow throttle response...I have had this boat for 8 years....pounded the living crap out of it and never had no throttle response...always a 55mph boat....where do I start???