I have a 91 200 gt on a champion. The boat normally runs 69.5 or real close with 2 people and tackle on gps at 5850 rpms. I noticed in a tourney that boats where outrunning me that hadnt never before so I re-checked it, 63.9 is all it would do. I changed the fuel filters, plugs, and ran a de-carbener thru it and got the same result's. I dont see any prop damage and the motor runs good but I cant figure the speed lost. It also is only turning around 5500 rpms. Im gonna do a compression test but was wondering what yall thought. Thanks