First of all let me say that I am in a small village in the Republic of Panama and finding a service technicians to work on a motor is difficult at best so it is mostly a do it myself deal. Also I apologize for the length of this post but just wanted everyone to have as much info as possible to be able to help.
I have a Mercury 2006 30HP 4 stroke EFI. I bought it new in 2006 and have run it 3-5 days a week here in Lake Gatun since and never had a problem until a couple days ago. I was running along about 3500RPM when the motor just shut down. I first thought fuel so I reached over and hit the primer bulb only to see fuel spray from about five tiny pin holes. Okay, yea I should have changed the fuel hose earlier but the motor cranked right back up and I was able to limp in running less than 2000 RPM. Once I changed the fuel line and then pulled the filter housing apart (yes it had trash in the bowl) I flushed the lines up to the filter by pumping the bulb with the housing open and then installed a new filter. Okay, it the key and it started right up. I then put it in neutral and pushed the throttle up to 4500 RPM and everything seemed normal. I then put in gear, pulled away from the dock and pushed the throttle up slowly. Everything seemed normal until i it got close to 300RPM and then it shuts down hard. The reason I say hard is that it does not sputter or act like it is running out of fuel. It just slams down and I can hear what I can only describe as a clacking noise. I can immediately hit the key and it wil start right back up. I thought then maybe it is the low pressure pump so I tried pumping the prime bulb while increasing the throttle but it does the same thing. I did feel that it was running a little rougher than normal and thought maybe something with timing but the belt looks new and tight.
So, I guess my questions are has anyone experienced this behavior and if so what did they find it to be? Secondly, if it is in fact the low pressure fuel pump, dos anyone have experience with changing out one on this motor? (It appears to be a real tight fit and depending on how much of the pump is inside the motor clearance between it and the motor housing, might require the head to be removed. )