Reply To: Mercury Mark 55E

[bbradb]

Update… Made some progress today. Checked compression and I was satisfied: 130, 125, 130, 125. Ran motor in barrel for a bit. Wondering about water stream from cooling system. As I understand it this is primarily to indicate that the pump is pumping water and that much of the water return is via the center of prop maybe. Is this correct? I took a video to show magnitude of stream but am unable to upload here. Hmmm. How can I describe? I’m an old guy with the typical plumbing issues if you know what I mean guys. I do about the same as the Merc, slow but steady and sure. My son felt it should be much stronger. We are suspicious that cooling could be an issue. I’m suspicious that this area has been worked on not long before we bought engine. The first video I saw of motor running showed no evidence of a water stream. When I talked to PO, he made a point of showing me impeller he had recently removed and replaced. Honestly, I wondered why he did that since he stated early on that motor “was completely overhauled” even if without a manual?? Wouldn’t a new impeller go in along with overhaul?

If I wanted to check impeller and water pump, where would I start? Manual seemed to start with “pull the lower end”.

Also, someone in thread indicated there was a plug high on the block that could be opened to check that water was getting up there? I couldn’t spot that. More clues please. Where is plug and what is purpose. Somewhere I read one could attach a gauge and actually measure water pressure? Is this true?

Thanks for all ideas.
Bruce