Yamaha 115 Two stroke 2008. Alarm and Limp mode issue

[rick3452]

Hi guys ! just got off my friends 17 foot Meiko with a 115 two stroke, runs fine both heads run 140? but it near wide-open throttle the alarm goes off in the engine goes into limp mode. The temperature on the starboard head goes to 170. The alarm goes off in the engine goes into limp mode . The temperature on the port side of the head remains around 150? When we unplug the sensors on the heads the engine never went into limp mode and ran perfect at high RPM's The impeller is fairly new and not many hours on the engine at all. Where would A good place to start be?

 

[99yam40]

lack of water flow due to bad pump, bad stats, plugged cooling passages, or lean burning cylinder could cause excess heat at high RPMs

I believe some of the Suzuki had a water level switch, but if undoing the overheat switch stopped it then level would not come into play

You could find out which one was setting off the alarm and pull that one to test in a pot of water as you heated it to see what temperature it closes at to see if that is in spec.