i have a 2002 hallet 255 mid cabin open bow with a hp500efi with 180 hrs. ive owned since 07 with 90 hrs. always thought it should perform a little better and seems to be slowing. with light load, light fuel, lab finish 26 bravo, slight chop lucky to see 70 mph (gps)@appx5k rpm . so i checked compression, reading 150 to 159lbs. the service manuel says minimum of 175psi. previouse owner and i baby this boat, probably doesnt have a half hour total @wot.it runs smooth and burns no oil. i thought i read somewhere these motors had some valve problems but i assumed that was under severe conditions like raceing. any thoughts????