2000 optimax 225 hp dfi no power

[Wreck_it]

I recently bought a boat with mercury optimax 225hp the problem is it runs fine when hookup to hose in drive way except little rough idle but above idle is fine put it in gear and it revs to 3 - 4000 rpms fine but when I put it in the water it will not go above 1500 - 2000 rpms any suggestions?

Thank you in advance

 

[JGTimeout]

Same question. Did you ever get an answer? My 225 Optimax dies when I put it in gear in the water after a mostly smooth idle for 5-7 minutes. Put fuel stabilizer in it and next step is spark plugs and then compression tests.

 

[vroom ZOOM]

check air and fuel pressure