I am working on an overheating issued on my 2000 Four Winns 170 with a VolvoPentaSx 3.0 (raw water cooling) . I think it's the riser which I plan to replace. I've pulled it off and it's fairly corroded and was somewhat clogged. In reading on this forum it sounds like after 15 years that is not surprising. While I have things off I thought I would put in a new thermostat and flush the system as best I can. I flushed all hoses, the exhaust manifold, the head and the block. I also ran water down the exhaust pipe below where the riser attaches to make sure it did not back up. I expected to see water come out of the holes just below the fin above the lower gear case and some out of the prop. While water did flow freely from those areas it also ran out at the bottom of the gimbal housing were it butts up to the hull. It looks like there is a little gap for water to run out and I am hoping that is normal and not a problem. Is it? Water also cam out of the exhaust billows but, again, I suspect there are small drain holes in it and that too is ok. Is it? It (the exhaust billows) looks to be in good shape and the water came out of a few holes along the bottom edge that seemed to be quite evenly spaced as if they were meant to be there. Any input would be greatly appreciated. I am not overly familiar with the terminology on boat drives so I hope I am making sense. Thanks!
