hello, i have a 2002 gtx di, i can only reach 5800 to 6000 rpm. checked the usual supects, raves, compression etc. now heres the kicker. i can go out on the lake and try to find the sweet spot for neutral on the reverser, i rev it up and it will go to 7100 rpms. but when i put it back in gear and go it will only do the 5800. any ideas?