Last weekend an alarm on my 2004 Mercury salt water 2 stroke went off when in gear with throttle was fully opened. After about 10 to 15 seconds, an alarm went off. I eased off the throtle to 3/4 and the alarm stopped. I checked the oil reservoir and there was plenty of oil and the water flow from the side of the engine was also fine, any thouight as to why the alarm is going off in gear at full throttle.