Bought an identical pair of 01 YAMAHA XL800's. Just finished replacing jet pump on one. After initial test here are the results

#1 : Runs rough low end, boggy rpm curve until maybe halfway where it opens up like a bat outta hell all the way to 7000-7100rpm or so. I saw maybe 73-7400 rpm out of the water. Hard to tell gauge plastic is beat up. Gps on smooth water was 45-46mph. 135psi both cylinders. 180lb rider

#2 : Has a steady rpm curve on low end but tops out at 6000rpm. Will do 7000 rpm plus out of water. Gps on smooth water was 40-41mph same rider. 130 psi both cylinders.

Holeshot is good on both (#1 good when rpm band kicks in). I dont think there are any cavitation issues. After research I'm leaning towards powervalves. Took #2 apart first. Everything seems to move smooth. Some sludge but not enough to make me lose so much top end I think? Pix attached.

20190705_125913.jpg20190705_125946.jpg20190705_130030.jpg