Changed circ pump - Scaling in water passages?
 

My circulating pump went and while installing the new one I noticed a decent amount of deposits/scaling in the the water passages (where I could reach my fingers into) and also what seemed like alot of black soot that is scraped from the edges of the holes.

Scraped a lot of it away but anything I can run through the engine to disssolve/clean this? Is a 3 year old long block Merc 454, RWC run on the Chesapeake. Currently there is no strainer for the RW just where it comes through the Bravo I. Would installing a inline strainer help? If so what size/capacity do I need?

Thanks

Re: Changed circ pump - Scaling in water passages?
 

That's just typical RWC engine corrosion and deposits. You'll see the same thing if you look inside the thermostat housing and a strainer won't help. Be careull about doing much scraping, you could loosen enough material to cause a clog elsewhere in your system.

Re: Changed circ pump - Scaling in water passages?
 

Use Salt Away to flush motors. Not that expensive, but works good. Read directions.