Not sure what else to try here??? Motor bogs down and stalls under full load. Things replaced/checked/repaired. Carbs rebuilt and new jets, new fuel pump, new power pack, 6 new coils, new plugs, compression @ 117-120 all cylinders, timing checked on the water is good, new fuel bulb, fresh gas, crank shaft resealed and no signs of any damage, lower unit replaced. This engine has been completely torn apart and no apparent reason why its doing what its doing. Engine starts and idles fine and runs great on a hose but as soon as its in the water and throttled it stalls out. Carb cleaner in the middle carb will get it over the hump but all the carbs have been removed, cleaned, new jets and rebuild kits 3 times now. Floats are fine too. Shop mechanics are completely baffled as well. Any thoughts/insight would be greatly appreciated! One other thing, the engine did overheat a cpl years ago as the water pump went out but upon inspection everything other than gaskets were fine. No scored cylinders either. HELP PLEASE!