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1999 200 HP Mercury EFI Loses Power

OutboardProblem

New member
Has been a great beast but it’s being a temperamental motor now. It loses power at various times and I’m looking for the root cause. Starts up idles and go to throttle up and bogs down. Shut it down wait a couple minutes and sometimes it powers up on plane and runs normally. So, clipping along at 3,200 rpm and it loses power and drop the throttle back to idle and powers up again like normal.
I’ve changed spark plugs, changed the fuel/water separator, drained the high pressure fuel tank reservoir and run rec gas only. Checked all the wires for connections/tight on coils and ground connections. Looking for some new ideas as to what I should do next for troubleshooting. Thank you to all the Members for your input. Edwin
 
Surprised that there was no response from members on this issue with my 1999 200hp EFI Mercury 2 stroke outboard. But incase someone has this lack of power and need to troubleshoot their motor here’s how I fixed the problem.
Pulled the coils and tested each with an OHM meter. They checked out. Ohm tested stator and trigger as well and meter readings were okay. So I decided to visually inspect the motor from the top down. Removed the flywheel, pulled the stator and trigger. The trigger showed visible signs of stress cracks in the housing. Replaced the trigger and reassembled for water test. It still bogged and had no power. Turns out the newly replaced spark plugs were fouled again. Replaced plugs and water tested again. 100% responsive and working. Visual inspection found the compromised trigger which failed once the motor heated up to operating temperature. Metered readings at normal ambient temperature showed it being normal. Finally replacement of fouled surface gapped plugs was also needed. Hope this troubleshooting helps anyone experiencing 2 stroke intermittent power loss.
 
Defective trigger. Cracked.
 

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