Thanks for the support...Yes, I pressure test my headers religiously; that was the first thing I thought when I saw the salt in the ports but they're not leaking; I tested them every way possible... submerged in water with 70 psi in the jackets, not a single bubble... filled them with water and then heated the primaries with a propane torch, not a drop. it's all from reversion... and the damage in the same cylinders on both engines supports that theory as well. Yes, it completely sucks to have to go through some pretty big expenses to correct a major design flaw but believe it or not, I'm kinda feeling lucky in a twisted way... I easily could have lost both rear engines (I've already replaced one long block) plus have to do all of the stuff I'm doing right now and potentially lose a good part of next season. And hey, it's winter... gotta have something to do ....

525's are bulletproof!!!

Just an FYI, the stock springs are not ISKY's, they are made by PAC.

We've seen quite a bit of reversion issues with silent choice as well. All of them could be traced back to either a cracked tailpipe or a broken, cracked or missing dam in the tail. In all of the tails that run silent choice, there needs to be a dam welded in the floor of the pipe to stop the water from creeping back up the floor of the pipe and into the header. It will not work without it and is a given that it will revert water. They have a bad tendency to come loose or break off completely. It really doesn't seem to matter much if you use the silent choice or not, unless you try to run wide open with it. Having it either open or closed at idle doesn't really matter. The water is still introduced too early. The dam typically runs from about 4 o'clock to about 8 o'clock. It's actually a small section of pipe and forms a pocket to catch the water. It gets welded near the flange and extends into the tail about 3" or so and is elevated off the floor of the pipe about 1/4" or so. As the water tries to climb back up the floor of the tail, it goes under that dam and stops where it is welded. That's why you will have some reversion if that weld breaks as there is nothing left to stop the water.
Eddie

Eddie do you happen to have a picture of the "dam"
Thanks!
Steve

I was thinking about it when I posted earlier. I will have to look through my pics and see. I just repaired one last week. It had completely broken loose and got wedged in the silent choice flapper and got all bent up. I had to do quite a bit of straightening to get it to go in place before I could weld it back in. I don't think I took any pics of that particular one. I'll see what I can find.
Eddie

Mine is getting new springs, retainers and keepers now. The headers are off. When I get the boat home I will look for those dams. Eddie, it's not getting the Isky springs I don't think. They are from Teague and supposed to be stock replacements.

I half ass drew this up. I hope it makes sense. I call it a dam for simplicity. I'm not really sure what else to call it.
It is welded only right near the end of the tail closest to the header. The rest of it sits only about 1/4" or so above the floor of the pipe so that any water that does climb back up the pipe will hit the end where it's welded and won't be able to go any further. The water would have to be deeper than 1/4" for it to get past the dam.
Eddie

Gotcha. When you mentioned ISKY's in your post, I assumed that you were using them. I remember you saying that you were going with the Merc stuff in earlier posts, so I was a little confused.

Hi, I am a first time 525 owner and reading all this makes me nervous! 2007 Baja 35 Outlaw, bought in Aug with 97 freshwater hours, most below 3000 rpm. Boat was surveyed and passed compression test. Had new plugs installedd since old ones were out. Anyone able to brag about 500 trouble free hours or anything like that? With the thousands of 525s in use, there has to be an equal number of great stories to horror stories. Right?