1985 Merc XR150 V-6, I have had it for a year and a half, total of 319 hours on boat/motor. I have put about seven hours on it due to recurring ignition/carb difficulties (see other thread). Anyway, finaly got that worked out just before the end of the season last year, and had two good one-hour rides before we put it up for the winter. <br /><br />Nice weather is back, so last weekend I ran it for 15 minutes on the muffs. Dropped it in the lake, fired it up, idled out past the no-wake buoys, throttled up to a moderate pace. Within 60 seconds I had the steady beeeeeeeep warning.<br />Headed back at low power setting, horn went out. Packed up and went home.<br /><br />Water temp read 190 when the beeper came on, although I have seen higher temps in the past and don't necesarily trust the gauge's accuracy. I replaced the water pump impeller when I bought it, and the water stream looks as good as it ever has.<br /><br />I opened the cowl and checked for pinched wiring, then checked the oil tank switch by the Merc manual (yes I have the Merc, Seloc and Clymers). Found next to nothing in any of these manuals about warning horn actuation and troubleshooting. I also shorted the overheat switch and the horn went off (long beep). <br /><br />Where to start? I guess first I need to determine, do I have an actual overheat condition or an indication problem. Can I use a meat thermometer on the outlet water, and if so, what is proper temp? Thermostat check? Warning switch? <br /><br />Thanks as always, I'm sure one of you knows what is going on
