Re: exhaust water hot
I seem to recall that a lot of these smaller Mercs don't have a steady stream out of the telltale, but rather it ebbs and flows with the cycling of the thermostat. Also, the water is usually warm not stone cold as you'd think.
Assuming this is normal, the block shouldn't be running more than 140 degrees; this is warm but you should be able to put your hand on it for a few seconds. If the block is so hot you can't stand to touch it, that's closer to 180 degrees and too hot!
Compare the warmth of the block, with the temperature of the exhaust manifold outer cover. The larger, flat cover on one side of the powerhead. All the cooler water flows thru the exhaust manifold cover passages, and if there's inadequate cooling the hot exhaust will heat the cover up rapidly.
Normally, the cover will be noticably cooler than the block on a thermostatically controlled motor. If the cover is hot, start worrying!! If it's just barely warm, or cool to the touch, you've got enough water circulating thru the block.
What year is your motor; quite new (I'm assuming so, given the low hours)?
If not, and it's older but with low time, you might consider installing a new impeller. Even though it's got low hours, if it's been sitting for years the impeller may be deteriorated, and should be replaced.
HTH...........ed
