90 degree elbows on raw water pump impeller?

[Les Luzar]

One other point not mentioned is that I have seen a 4 year old HX 90 degree exhaust elbow become completely plugged with a hard calcium grit like substance so it would be a good idea to inspect these elbows whenever possible. If exhaust raw water flow seems to be restricted, at least this is something to be aware of and inspect.