I am helping a friend with his boat and it is a Triton 186 magnum aluminum with a merc 150efi and manual jack plate. For some reason his boat is breaking water about 5 foot in front of the windshield trimmed up. When everything was running correctly in the past, it would break water on plane at the drivers seat. I raised and lowered the jack plate at 1/4” intervals and test drove and nothing made a difference??
His tach is not working right now and I know that would help me to see optimal performance, but I thought surely An inch or so either direction would tell me something. The prop is not bent, but I wonder if the hub could be slipping that much ? The motor is not over-reving as far as I can tell ?
Thanks in advance for your input.

prop may need to be worked for bow lift, may need more pitch.

what set back is the jp? where did you start to raise/lower from, 3.5" below pad is normal starting point.

http://www.stevescustomprops.com/faq.html#How_do_I_adjust_the_Prop_shaft_engine_height_