I recently bought a '04 29' Fever with the 525 EFI and am looking into putting silent choice exhaust on it since the fuzz can be a little hard on the noise on the St. Croix River in MN. I've read dozens of forums saying its ok if you keep the rpms down and others saying its not ok. Of course Mercury said don't use it at all on the race motors and that they've never tested it. All I really want it for is the no wake zones, thats where I'd get in trouble. So I'm looking for opinions or facts on if silent choice will work with this set up at idle or slightly above without getting water reversion from too much back pressure. Ideally it would be nice to get the facts from someone with the exact set up and which brands work the best. I read somewhere that certain ones (I forget which brand) start opening after some hours are put on them, not sure who makes those but that would suck. Thanks for any info, its much appreciated.

I have a HP 500 that came with silent choice. All I use it for is close to marinas at night. Never plane with it. When I throttle up for some time (still not on plane) they will open up. Simply hit the switch again.

Works great keeping the sound down. I don't want to be a nuisance around the docks at night. Any other place or time I don't care.

Reversion happens at idle not while on plane. Seen several high HP motors with choice on them.

I have 525EFI's with Silent Choice and I NEVER use it. The 525 cam is aggressive and I never use the silent choice because of even the slightest possibility of reversion. The way I see it, getting a noise ticket still a lot cheaper than what happens if you get reversion...

Not a great idea on the 525 the cams love to suck water back,the silent choice seems to work ok when the motors are fresh but once the valve job goes away you will have reversion,i would put a set of switchable mufflers on transom,merc racing also states a bad idea

I think I'm going to just go with a set of turndowns so I can put them on when needed.

Switchables and Silent Choice are not legal on the St Croix anyway.
The turn downs or full time mufflers are what you need.

Yeah I know there not legal but the cops aren't that bright and you just don't switch it right in front of them. Turn downs it is

Turn downs for what.....



Sorry, couldn't help it

I remember one that had a hp500 that had some odd resonance with the platform on the boat we installed some inserts from imco I believe it was and packed it with a mix of stainless mesh and carbon fiber strands ,didn't affect power ,cured the annoying resonance at idle ,that was prob from the hinged flappers made a dramatic difference in the sound quality ,it was like going from being inside a camaro with open headers to standing behind a brand new gto judge . Ran modified rubber 4 " splash back flaps from a centurian .