I am going to try and be as complete as I can with the issues and repairs of this motor. So bare with me!! It all started when I purchased my pontoon 2 months ago that is powered by a Mercury '04 90hp ELT 2 Stroke. The guy I bought this 'toon from had not had the boat in the water for over 2yrs and the carbs were all gummed up and needed to be cleaned desperately. The seller had the carbs all cleaned up before I purchased and the 1st boat mechanic said they were as good as new. Bought the boat, launched it in the river didn't get 100 yds and the motor sounded and felt as though it was starving for fuel...took the boat back to another mechanic..now mind you this mechanic works for a marine service center where I live and does repairs on the side at his own shop. He has a great reputation as being a top notch/best outboard mechanic around for all outboards including Mercury. I now have had this motor to him "8" times in 2months !! It's the same story...carb has crap in it...cleaned and flushed fuel tank, replaced inside and outside fuel lines, installed water separator, rebuilt fuel pump, cleaned and rebuilt carb 3 times. Last time he messed with the carb apparently the needle wasn't seating right in the carb which he said was causing us to be only running on two cylinders...Called me and said it will run like new...Yeah right! Swears that the fuel pump is ok and not required to be replaced. Replaced primer bulb.. Boat will run great the next day after repair. Take it out a day or two later and it will idle fine but when put under load will go from 30 mph at 3000+ rpm down to 5 mph at 1000 less RPM. Will surge w/power for 2 sec's then die to barely an idle. Will do this until we can gimp it back to the boat launch at 2 miles an hour. Now, mind you I'm not an outboard motor mechanic with the certifications from the Mecury motor to work on this motor... He does. And he can't find out what is wrong with this motor. Now, he's talking that it could be the coils or a power board. Advice, feedback opinons are greatly appreciated!!!
