"I recently bought a jon boat with a 60hp mercury on it. The guy I bought it from is a marine mechanic and said he totally rebuilt the carbs. Here is the probelm.
When I have the hose hooked to the motor it runs great. I can gas it full throttle in neutral, forward, and reverse. The problem is when I put it in the water and put it into gear. When I try and go full throttle then it bogs down and cuts out. It only lets me give it a little gas and put along. When I push further on the throttle it bogs out. The same thing happens in reverse on the water. If I put it in neutral on the water it will let me rev it up fine. What could this be?"