--------------------------------------------------------------------------------<br />I have a 1985 Bayliner with a volvo penta I/O AQ125/270 that has overheated all year long. After extensive repairs and expense I have given up on the local dealer.<br />The following have been repaired or replaced with no improvement.<br />The raw water pump impeller and seals and water tube seals. The lower units water tube and seals. Radiator cap, pick up tube seals and bushings and bearing. New anti-freeze mixed at 50/50 ratio. Currently there is no thermostat in the engine but I will install one tommorrow and try it again.<br />The unit only overheats with the engine rpm above 3300 or when pulling a skier above 20mph. The faster I drive the quicker it overheats, and conversely I can run all day long under 3000 rpm and it never gets hot. When hot it has a great loss of power and rpm's drop as well.We were told that the lower unit was probably sucking air and that is when we replaced all the lower unit seals and bearing. We have run it with a garden hose hooked up to the intake port hose and it will not overheat at all! No matter how high the rpm's and therefore I think it has to do with the load or torque demand placed on it.<br />Any help would be greatly appreciated and if anyone is hesitant about volvo lower units and has any questions about them please ask. We have devloped quite system for removing and repairing it and can do most repairs in about an hour now. haha What a way to gain experience.<br />We thought the overheating was initially from a low grade octane gas that was accidentally put into the boat. We competely drained the fuel system and put top quality premium fuel back into it and it did help by about 10 degrees or so.<br />The engine seems to be running about 230 degrees when very hot and will idle along at 170 the rest of the time.<br />Any one experiencing the same and having answers would be great.<br /><br />Thanks for the help.<br /><br />Michael<br />Zakiah7
