Last year I installed Stainless Marine wet exhaust, water doesn't exit till the very end of thr pipes. Risers go through the transom and also have a very large radius up by the manifold. These are like the merc 525 set up. I had some other none related problems where I had to remove one of the heads, after I removed the intake I noticed that there looks like there is some water getting into the intake and exhaust ports. It appears only the rear cylinders are having this problem. I really never got alot of run time last year, did do alot of idling and running on the trailer. I have small Hydraulic flat tappet cams which is what was in there when I bought the boat. I did install Dart Iron Eagle heads because the heads that where on the engines were leaking. I just can't see how the water can get sucked all the way up this riser. I've talked to a few people and really can't get a definete answer on why or how this is happening. I'm not sure if I'm making more out of this than it is or not. It doesn't appear that there is any water in the cumbustion chamber, just the port areas. Head gaskets look like they are sealing well, didn't see any problems there. I'm wishing I went with the dry exhaust now but I didn't want to have to spend another $3000 on mufflers. If anyone has any ideas I would appreciate it.