Lost speed.

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

Heat and humidity will drop your speed. You should see it pick back up in the fall.

I did a compression test last night, the results where.
80 90
90 90
80 90
in that order looking at the back of the engine.
Would this make it lose 6 or 7 mph?
I plan on taking it easy the rest of the summer then re-ringing and bearings during hunting season.

Heat and humidity will drop your speed. You should see it pick back up in the fall.

All my gps readings have been in the middle of summer, heat could change it 2 mph or so but I wouldnt think 7.

Comp numbers look OK. Pull the carb drain plugs and make sure the HS jets are snug in the carb bowl. Make sure the plates are opening full at WOT check the plastic roller on the linkage is making contact with the arm.