late 60's Merc 1100 no power?

Hi I have a late 60's merc 1100 110hp outboard and it runs perfect on land(with Ears) but has no I mean NO power in the water idles fine but when you go to push the throttle it just bogs and goes no where.....:reddevil:
also sucks back the fuel so I know its getting the gas and it has great spark and compression but I am lost as to why it will not rev out under any load IE In the water???
any help would be greatly appreciated as this boat is the only way for me to spend and real fun time with my wife and 2 young kids as im losing most of the use of my legs :nonod:

also someone told me that in the leg where the water pipe goes in there are 2 holes that it can fit in and I might have it in the wrong hole? seems wrong to me but I did just replace the impeller and service the rest of the leg! got my wife to do most of it! so is it possible that the water pipe is in the wrong hole and causing it to push water where it should not be? I know it looks like there are 2 holes in the upper leg.