Hi everyone!
I'm in the process of doing the yearly maintenance on the boat (1997 Rayglass 670 Sportsman, engine is a Mercruiser/VM/BMW Marine D530-TA).
I noticed that, while idling on muffs, a huge stream of cooling water comes out the exhaust relief port on the starboard side, the occasional mist out the prop, but absolutely nothing on the port side relief port. (I should mention that it has done this since we got the boat, but only after seeing videos of other Mercs online did I realise there are in fact two relief ports)
I also noticed that, while idling in the water, there's a significant amount of exhaust coming out of the prop, which I understand shouldn't really be the case.
I had a look at the "Y-pipe" (in this case just a J-pipe? Inline engine and all) and it definitely has a tube going to each relief port on the gimbal housing, i.e. nothing blocked off there.
I stuck a borescope up the relief ports - with the starboard, I can go straight through to the J-pipe, no worries. The inside is also pretty dirty, as you'd expect.
On the port side, I can't get deeper than a couple of inches before I hit something solid. My borescope has about the same camera resolution as a stick, so I can't tell what it is.
I removed the exhaust elbow and stuck the borescope down there too. Where the divider starts coming in in the pipe about halfway down, if I put it down the bottom division I can scope all the way down but if I put it down the top division, I run into a deep puddle of standing water down the bottom of the exhaust.
There appears to be a solid and water-tight blockage of the port-side exhaust relief port.
Is this normal? If not, how do I go about trying to get it out?
Cheers!