swflhummer
Seaman Apprentice
- Joined
- Dec 14, 2010
- Messages
- 34
Hey guys, I haven't logged in a very long time because I have M.I.A. Anyways I am now a Entry Level Tech at Palm RV & Marine here in Fort Myers and I am completely puzzled. I have been fighting this 2004 Mercury 90 Saltwater edition for about two weeks now and I will explain what all I have done with this to better explain the issue.
Problem #1: Owner (boss) buys the boat and was untouched for about 20 days. Customer comes to look at it and wants a sea trial so we take it out to Sanibel for a test run. Get it in the water and refuses to stay running with no choke.
Observation: Water in fuel.
Solution:syphon all gas out, fill it up, and syphon again. Added 15 gallons of fresh gas and flushed the lines out then hooked back up to motor. Pulled carbs off to get it all out. They are clean as the day they were made, ran motor on pavement with hose for approx 20 minutes. NO problems.
Problem #2: Customer comes back for another sea trial. Get it out on the water and everything is running great for about 2 minutes. Completely lost power! Eventually started back up and idled it back to the ramp.
Observation: 2 Yellow Wires going to the rectifier are melted together along with one other red wire.
Solution: Cut out wires and order new spools of wire from land n sea and replace wires with marine butt connectors. Motor is running again.
THIS IS THE ONE I CAN NOT FIGURE OUT
Problem #3 which has been fighting me for a week!: Boat will run great for about 5-10 minutes WOT all day long, temps normal, pissing well. Then it just drops from about 5600 to around 4900roms. It will go back in forth as if I am flipping a toggle switch for one of the cylinders off an on repeatedly. Which makes me think this is not a fuel related issue since it does not bog and stay at a certain point. It will do this through all RPMS except idle or just above.
Observation: Spark tester shows it has strong spark on all cylinders during all conditions. Motor is not running hot, Pulled carbs and once again clean as a whistle. Does not appear to have air in the lines.... What in the world could it be?
Solution: No clue. :facepalm: Help
I hope I have explained enough. I tried not to keep anything out but you know how that goes. Maybe ill go Oh yeah!
Problem #1: Owner (boss) buys the boat and was untouched for about 20 days. Customer comes to look at it and wants a sea trial so we take it out to Sanibel for a test run. Get it in the water and refuses to stay running with no choke.
Observation: Water in fuel.
Solution:syphon all gas out, fill it up, and syphon again. Added 15 gallons of fresh gas and flushed the lines out then hooked back up to motor. Pulled carbs off to get it all out. They are clean as the day they were made, ran motor on pavement with hose for approx 20 minutes. NO problems.
Problem #2: Customer comes back for another sea trial. Get it out on the water and everything is running great for about 2 minutes. Completely lost power! Eventually started back up and idled it back to the ramp.
Observation: 2 Yellow Wires going to the rectifier are melted together along with one other red wire.
Solution: Cut out wires and order new spools of wire from land n sea and replace wires with marine butt connectors. Motor is running again.
THIS IS THE ONE I CAN NOT FIGURE OUT
Problem #3 which has been fighting me for a week!: Boat will run great for about 5-10 minutes WOT all day long, temps normal, pissing well. Then it just drops from about 5600 to around 4900roms. It will go back in forth as if I am flipping a toggle switch for one of the cylinders off an on repeatedly. Which makes me think this is not a fuel related issue since it does not bog and stay at a certain point. It will do this through all RPMS except idle or just above.
Observation: Spark tester shows it has strong spark on all cylinders during all conditions. Motor is not running hot, Pulled carbs and once again clean as a whistle. Does not appear to have air in the lines.... What in the world could it be?
Solution: No clue. :facepalm: Help
I hope I have explained enough. I tried not to keep anything out but you know how that goes. Maybe ill go Oh yeah!
