2008 Mercruiser 4.3 MPI losing power

[dbordes]

I have a Mercruiser 4.3 MPI in a 18’ Four Winns. The engine starts right up and idles fine. As soon as I apply the throttle I am not getting vibrations and a loss of power. I could not get more than 2000 RPM. I had a similar but less severe issue earlier this year. I replaced the fuel filter and put in a bottle of Sea Foam during the last fill up and that seemed to correct the issue. My first thought is to perform a compression test and replace the plugs. Any other thoughts on what could cause this?

 

[makomark]

i'd check fuel pressure...