75hp Mercury 2stroke 2008 Starting problem

Many thanks to all for your input , I have taken plugs out and they were blackened , did a compression test few months ago and they all were equal over 150psi , Would diagnostics pick up on sensor for fuel injection. ? The engine runs lovely ,accelerates smoothly, plenty of power ,no smoke ,idles fine ,if slow trolling the buzzer goes off after few minutes to check engine but shows all ok
I’m not sure what the diagnostics might show, but my suspicion is that it’s not richening the mixture for cold starts. It fits the symptons.
 
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Thanks for that info , how does the mixture get enriched on cold start ?
As its a direct efi motor, there’s a temperature sensor which feeds back to the management ECU. The fuel is regulated by the ECU, hence my theory of the faulty sensor. You may be able to use easy start or similar sprayed into the air intake to get around it short term
 
I have no experience on this motor. But from a brief google, there’s lots of more technical advice, including how to troubleshoot it. I found a guy from some muddy creek in Georgia last time I had a mercury problem, he was absolutely stupendous. A fair few really goid ‘how to’ vids seem to be out there. Check if it’s working before buying, if you can, they are £70-£90. But it just screws into a thread on the motor and plugs into the loom. How hard is that?
 
I have no experience on this motor. But from a brief google, there’s lots of more technical advice, including how to troubleshoot it. I found a guy from some muddy creek in Georgia last time I had a mercury problem, he was absolutely stupendous. A fair few really goid ‘how to’ vids seem to be out there. Check if it’s working before buying, if you can, they are £70-£90. But it just screws into a thread on the motor and plugs into the loom. How hard is that?
Many thanks for your replies , that certainly gives me something to go on ,much appreciated.
 
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