2006 mercury verano 275hp instant cuttoff

seawolf3000

Recruit
Joined
Jul 13, 2019
Messages
1
Dear boat fanatics,




I am the owner of a boat with two Mercury Verado 275hp 4-stroke engines made in 2006 that have been giving me a hard time for quite a long time.




Symptoms

When I accelerate at one point one of the engines suddenly cutoffs instantly (stops working completely) which is something you feel since your head jerking in the front and then after that split second the boat engines come back to working. When this happens the RPMs on the cluster are going up and down like crazy and specifically when the RPMs drop you can hear a beep sound. The instrument displays a “Check engine” warning.




When I input the gear into neutral the left engine switches off completely.




Also, sometimes I’ve noticed that the RPMs on the engines were different (4K and 3,5K).

My guess is that there is an issue with the engine on the left but since the engines are mirroring each other the right engine is also being affected by the left.



We have tried to run diagnostics tests but it doesn’t show something.

The only thing we managed to notice when we measured manually is that there was a different voltage between the engines and the control.

Checked the isolator which is between the engines and the battery and nothing wrong with it.




What we tried fixing so far

1. We have changed the wiring of the boat

2. We have changed all the fuses

3. We have changed the battery




After spending a considerable amount trying to fix this issue you probably understand my frustration. Posting on this forum is my last chance to try and trace the issue before going ahead and replacing the engines.




Any help will be much appreciated. Unfortunately I am based in Greece otherwise I would gladly visit any local dealerships in the US.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,501
First thing I would do is monitor the circuits actuated through the key switch(s).

Could be bad contact(s) and or a loose connection at the switch
 
Top