1969 Mercruiser 160 I/O Overheating

[sailor3X7]

I took my 1969 Mercruiser out on Saturday. Didn't get to stay out too long because the engine temperature went into the "red". I got it back to the dock and on the trailer (hopefully with no permanent damage) Engine oil was okay. My suspicion is the water pump.
What is the best way to determine if it is in fact the water pump? I don't want to replace it only to find out it was something else.
I have a week long lake trip planned for the end of July and need to repair it before the trip.
Is the water pump replacement a relatively simple procedure on that engine? (I'm not much of a mechanic, but I think I can swing this one if that's what it is.) Any suggestions?

 

[Reel Poor]

Re: 1969 Mercruiser 160 I/O Overheating

If the water pump hasn't been replaced inside of two years or you have cranked the engine on the trailer without muffs, replace the raw water pump. Probably would be a good idea to also replace the thermostat.

If the engine ran with little or no water supply, the rubber exhaust boots are probably damaged also. They should be inspected.