1992 Mercury Outboard Overheated

[Ceilingwalker]

Hello. I was running my 75HP Merc and the water pump quit. Unfortunately, I didn't realize it until the motor became incredibly hot, made some odd sounds, then stopped. I purchased and installed a new water pump, now it pumps water like a champ. The issue I have now is that it idles really rough and the motor sounds odd, like there is banging going on inside of it. It starts nicely and runs alright, other than the sounds it is making. I tried to find a maintenance manual for it online but had no luck. I am wondering if anyone would have any tips as to finding out why it is running and sounding a little rough? Thank you.

 

[racerone]

Compression test first.------If there are low numbers.------Find the cover on the PORT side of the motor.------Remove 18 bolts or so.----Remove covers.-----Inspect pistons & rings.----It does sound expensive.

 

[Texasmark]

I did that with an old Evinrude 70 hp Before the days of the tell tale and alarms....thermostat froze shut and no bypass valve for high speed operation. Cost me $1k and I did all the work but the machining work part....years ago.