R/R means remove and replace.
The raw water pump has a rubber impeller and pushes raw water from outside the boat up toward the cooling system.
The circulating pump is what you think of in an automotive application. The water pump in a Chevy truck is called a circulating pump on your Marine...
If the manifolds were cracked on the outside, good chance they were cracked on the inside (exhaust side) also. That’s why it dumped water into the cylinders.
With your admitted lack of knowledge. Get a surveyor and have them give it a pre purchase inspection.
The survey should include both out of water inspection as well as a good in water evaluation.
20-30 minutes of run time including brief WOT operation should be included.
A good surveyor...
There are 2 oil seals between the upper and lower housings.
Have you ever had the drive separated ie, removed the upper from the lower?
Maybe the seals are leaking or if it was recently done, possibly didn’t seal correctly?
They are O-rings that just sit in grooves.
Check it part number...
32 gallons across 2 motors.
So 16 gallons per hour each cruising.
1-2 gallons per hour idling.
The 8-9 gallons per hour was a guesstimate across all hours of usage.
How many total gallons did you use last year?
Hours may not be the best correlation between marine and auto engines.
Gallons of fuel used may give a better perspective because marine engines operate at much higher loads than auto engines.
I average 6.5 gallons per hour throughout the season in a 24’ boat. That’s 12-15 gph cruising down...