motor problems

Hi I currently own a 96 175 FastStrike; model # J175GLEDB serial # G04061097. I used to get 62-64 mph tourney loaded at 5600-6000 rpm's. About a year ago I had transom work done so they had to take the motor off. Since then; not sure exactly when problem started; Ive had a loss of tyop end speed; now running 55-57mph and 5200-5400 rpm's with a noticeable difference in hole shot with live wells full. I'm turning a 14 1/2 X 24 Raker that had some nicks (not bad ) but had it fixed. No difference in performance. Motor height is 2 3/4 ". Should I start with a copression check. Any suggestions PLEASE.

Could a change in motor height after the transmon work cause a change in rpm's. I feel I need to get the epm's back to where they were.

Yes measure your pad to lower unit height is should be around 3.5" from the center line of the LU to the bottom of the pad.

If I lower the motor wont the rpm's decrease further.

I'll just throw a couple of things out there based on what I've learned while here at BBC... Could the transom work have possibly changed your transom,trim angle?
Was 2.75 your engine height before transom work? Sometimes ( depending on set-up) an over exaggerated engine height ( 10' rooster tail )= prop slip= loss of lift=
hull friction= loss of speed & r.p.m.s. Sometimes a lower setting gains you lift
which translates into speed & r.p.m.s. Sounds like your issues started after transom work. It would really be a coincidence that the ALLMIGHTY Fastrike would start acting up at the the same time as your transom work,but,stranger things have happened. I would personnally look into my setup first,unless your pretty
confident that has not changed.
Hope this helps a little
Good Luck

Could one of my plugs be not firing. I figured the loss of 1 cylinder would have a greater effect though.