55hp jonson outboard wont run in water

[transamjegs]

i have a 1969 55hp johnson runs all day on muffs, starts on first turn everytime, put boat in water, motor falls on its face. its like someone turns the key off. i have checked compression, 122 on all three cylinders, cant seem to figure this one out. anyone have any advice on whats going wrong with this motor?

 

[boobie]

Re: 55hp jonson outboard wont run in water

Do a cyl drop test on it and see if it's running on all 3 cyl's.