1986 merc black max oil injected bogs real bad

[84warrior]

ok i have read the other bog thread but it is different from my problem
its a black max 150hp
ok so the engine will start and idle just fine when i run it in a barrel it runs perfect and will rev up and go like he$$.
but i take the boat to the lake put it in the water it will start and idle but will not go it just putts around.
after a wile tho and some throttle shoving it will get up and go up to 60 and cruse fine runs like a top
so i have checked everything on it to fuel leaks,to carb problems, to oil pressure, injection pump, everything
but everyone is saying cabs or fuel pump i cant test the fuel pump because i do not have the tools for it

so any help would be appreciated

 

[racerone]

Fuel pump can be tested by using the manual fuel pump !--------Does anything change when someone operates it.-----They all run perfect in a barrel in nuetral because there is no load ( work to be done ) not a good test at all.-----------These motors will sound quite good on 5 cylinders so make sure it is running on all 6 , by using a timing light to check spark on all of them.----Compression testing is also a good thing to do.