2000 / 2001 Johnson 50HP - HELP!!!!!!

WHY DOES IT RUN GOOD WHEN ITS HOOKED TO THE WATER HOSE, AND NOT WHEN ITS IN THE WATER?!?

I have a Johnson 50HP, either 2000 or 2001 year model...

Bought the boat/motor about 4 months ago, and haven't had a problem with it, then on June 12th, took it out to the river, and the motor wouldn't start, after working with it 20 mins, it started, but wouldn't go over IDLE speed, even when I had it at full throttle.. Took it home, checked the fuel lines and filter (all clear ) checked the 2 spark plugs and they were gapped at .020, and they were suppose to be at .030... so I re-gapped them to .030, hooked up the water hose and the motor started right up, and would run full speed!!! problem solved, so i thought... took it back to the river on the 19th, and same problem!!! took it back home, hooked it to the hose, and it ran fine!!!

WHY DOES IT RUN GOOD WHEN ITS HOOKED TO THE WATER HOSE, AND NOT WHEN ITS IN THE WATER?!?

Re: 2000 / 2001 Johnson 50HP - HELP!!!!!!

Runs ggod on hose not on water, there is no restiance on hose, should run good in reverse because of lack of restiance on prop