Low idle alarm

[mkshearer]

I have twin 2000-250hp Yamahas
On the one engine after I am idling for about a minute, I get an alarm. I have changed the water pump, thermostats, temp sensors, and checked the O2 sensor, If I keep the rpm's at 800, the alarm does not go off. I can troll all day at 800-1200, but when I pull back to 600, the alarm goes off. I don't know what to do next.

 

[bowhuntrrl]

Re: Low idle alarm

Check the poppet valve. This is the symptom that the give when malfunctioning. Also make sure your thermostat is good.

 

[mkshearer]

Re: Low idle alarm

Both thermostats were replaced. Where is the popit valve. I need to pull up the parts breakdown again. I don't remember seeing that.