I'm planning on putting exhaust turndowns on my 29' Fever 525 and am just curious if water reversion up the pipe is a concern when slowing down?

Had same question! I guess its not a problem but still curious!

Not sure turndowns are such a good idea with 525's. How long are your tailpipes before they exit? I just had major reversion issues with 525's and Silent Choice..

I just looked at some pics (boats in storage) and it looks like from the header collector to the transom the pipes are probably 16" - 18" and they probably stick out 2" outside. Definitely not using silent choice.

I have read that they sometimes use a weep hole on the underside of the turndown pipes to prevent the siphon effect from bringing water back up the pipe. If that is what you are concerned about, I don't think it is that much of a problem, but I don't have first hand experience with the turndowns. If you are concerned about water coming up the pipes when backing up or something similar, I think the internal flappers should control that.

we put a hole on the top of each pipe to break the vacuum.motors were KE725's in and OL.

A hole? You must have exhaust fumes and water coming out of there while running for sure? Don't you'?

I think he means a hole in the top of the turndown pipe. Doesn't take much to break the vacuum.

Still dont think it's a good idea, anything that pushes water back up is no good with 525's...

exactly