115 HP Merc Optimax sensor alarm goes off at 4,000 RPMS

[Bbots11]

I have a 19 ft Trophy that has a 115 HP Mercury Optimax outboard that has been working like a charm. It is set up with a SmartCraft gauge and the problem is that it sends an alarm anytime I go over 4,000 RPMs. The loud beep is joined with a picture of an engine and bell on the screen. As soon as I throttle back the alarm goes away. The engine is running between 98-118 degrees, the thermostat, water pump, fuel filter were just replaced about a week ago and then this problem started happening. I would think it is a thermostat problem but it was just replaced. Any insight is helpful, thank you.

 

[Bbots11]

Re: 115 HP Merc Optimax sensor alarm goes off at 4,000 RPMS

I have a 19 ft Trophy that has a 115 HP Mercury Optimax outboard that has been working like a charm. It is set up with a SmartCraft gauge and the problem is that it sends an alarm anytime I go over 4,000 RPMs. The loud beep is joined with a picture of an engine and bell on the screen. As soon as I throttle back the alarm goes away. The engine is running between 98-118 degrees, the thermostat, water pump, fuel filter were just replaced about a week ago and then this problem started happening. I would think it is a thermostat problem but it was just replaced. Any insight is helpful, thank you.

I just read a previous thread of someone who seemed to have the same alarm symbols of a flashing bell and engine symbol. He said he replaced the IAC (Idle Air Control) module, has anyone heard of this?

 

[on_ice]

Re: 115 HP Merc Optimax sensor alarm goes off at 4,000 RPMS

Does your motor have a poppet valve? What year is it? How long has it done this?

 

[Bbots11]

Re: 115 HP Merc Optimax sensor alarm goes off at 4,000 RPMS

Does your motor have a poppet valve? What year is it? How long has it done this?

I think it has a poppet valve but not 100% sure. It is a 2004 115 HP Mercury Optimax 2-stroke. It has happened the last three times I have taken the boat out.

 

[Nitro482]

Re: 115 HP Merc Optimax sensor alarm goes off at 4,000 RPMS

I think it has a poppet valve but not 100% sure. It is a 2004 115 HP Mercury Optimax 2-stroke. It has happened the last three times I have taken the boat out.

I had a similar problem....My alarm would not be consistent. Only came on during takeoff and while running on plane at 4000rpms..would quit when I went back to idle. mine ended up being a neutral safety switch.