I took the boat out again today on a local lake to try and get this alarm to come on again (see the previous thread here). After about 4 minutes of idling out of the marina, I throttled up to about 3300 rpm (22mph), and the alarm came back. I imeediately throttled back, and the alarm stayed. I opened the cowling to check the engine block, and it was about 140degrees as I suspected, and water was coming out of the telltale just fine, and was also approx 140degrees. I shut the engine down, tried changing the batteries to see if it was a loose ground in the switch (one of my recommendations by others) and when i re-started the alarm came back. I shut down again, pulled the main connector to the control box for about 10 seconds, and plugged it back in. Restarted, the alarm came back. About 30 seconds later, the alarm went away, and didnt come back all afternoon. <br /><br />I ran the engine at 3000-4000 rpm all afternoon and the alarm NEVER came back. I ran at idle, WOT, mid rpm, etc. The engine runs like an absolute top. Previously when the alarm had gone off, all my gauges went down, almost like a breaker blew. <br /><br />i'm starting to think this is a faulty overheat alarm. I cant find anything in my clymer regarding overheat alarms, sensors, etc etc. Does anyone think this could be the sensor? I thought it was the control box previously, and I stiull havent ruled it out... I'm going to pick up a heat crayon at napa just to make absolute sure the block isnt overheating - i dont think it is.
