Originally Posted by djmarchand
I both inspect these items and watch for symptoms that are caused by them, but I do not replace anything proactively other than filters, impeller and probably the transmission oil cooler soon.
I have done the same, for 6500 hours on my 26-footer's Volvo KAD44P. No transmission on this sterndrive boat.
Replaced the seawater pump at 5200 hours, probably could have rebuilt it. Replaced the exhaust elbow at 4100 hours. Have not touched injectors, injector pump, or internal coolant pump.
Replaced Balmar 912-75 alternator brushes at 1500, 2100, and 3200 hours (no idea why brushes needed it), and have not had to touch them since.