Plagued by overheating at higher RPM's on port engine (some heat buildup on stbd too.) Did usual: new thermostats, new water pumps, rebuilt pressure relief valve - no real help. Engine rigging unchanged since installed in 1995.<br />Have seen internal corrosion at top of lower unit between water intake and exhaust passageways allowing seepage of hot exhaust into cool water intake. High RPM overheating fixed by patch. Suspect same problem now at different point in lower unit. Anyone with similar problems/experience? <br />Engines well maintained -350 hrs. Want to consider this lower unit corrosion before removal of cylinder heads or power head - could get expensive.
