Hello all. I recently did an oil change on my 1991 Johnson 150 lower unit. When I opened the lower drain plug a large volume of water came out approx 1 pint, followed by some black sludgy oil. The magnetic screw had no metal filings on it to be concerned about.. I did a pressure and vacuum test on the lower unit and it held steady at a high pressure. I refilled the lower unit with new oil. I proceeded to check the propellor shaft by rocking the propellor from side to side and I did notice a slight amount of freeplay, maybe 1/8 inch. Do I have anything to worry about? Should I run this motor for a few hours then recheck my lower unit for water invasion? Where would thew source of my leak be if my pressure checks oK ? Are there any recommended tests that I should do before I take the boat to the water?? Response is sincerely appreciated.
I did notice on the lower unit body what appears to be a paint discoloration and flaking, probably from overheating in the area of the prop shaft, but the last time I run the unit it ran ok. I just dont want to experience and lower unit seizures so I am asking for advice and suggestions. I have pretty good mechanical skills although I am not a Boat expert.I can pretty much follow technical instructions quite well.
I did notice on the lower unit body what appears to be a paint discoloration and flaking, probably from overheating in the area of the prop shaft, but the last time I run the unit it ran ok. I just dont want to experience and lower unit seizures so I am asking for advice and suggestions. I have pretty good mechanical skills although I am not a Boat expert.I can pretty much follow technical instructions quite well.