I recently purchased a small boat with a 60 HP johnson 3 cylinder. I am not sure of the year but I think its an early 70s model. The motor runs fine out of the water. When I put the boat in the water it started fine but when put in idle it stalled. It also stalled when put in gear. I cleaned the carburators w/ carb cleaner and now it will idle for a minute or two w/ no hesitation. Then engine runs very well when put in neutral and given throttle all the way up to about 6000 rpm. when put in fwd or rvs it now goes but when given more gas it bogs down and stalls.