500 EFI Reversion
 

A quick question, I have a friend who runs silent choice on a 500 EFI and CMI made the pipes for him with only 8.5" of drop. The bottom line was the 2 back exhaust valves got eatten, to make a long story short can you run silent choice on a 500EFI? The heads are out at the machine shop getting done.

From personal experience I don't see why not.

I run a 500EFI with standard exhaust (Gill is it) and Corsa Quick n Quiet silent choice all factory installed by Baja on a 25' Outlaw. Have even idled backward with silent choice enabled.

No problems so far.

Donzi, I have a 1999 27 foot Formula FasTech with a 500EFi and Corsa's Captain Call (through the hub diverter), Formula told me they would not put the Silent Choice on because of back pressure blowing the 500's if left on through the hub. My Corsa open's up (goes to through the hull), either automatically or the silonoids can't hold the diverter closed I don't know which, at about 1800rpm. Have never had a problem.:cool:

Kinda confused, why would someone use silent choice @3000rpm?! I only use it in no wake zones <1500rpm; otherwise, let it roar.

Slow Wake zones you say? Guess that shows my boating experience, thanks for the tip.

Donzi26zx. Here on the west coast, we refer to silent choice as silent death. Your friend might want to check with Mercruiser to see if silent choice would void the warranty. My guess is yes. The only muffler system we recomend is Shot Guns. They still allow the water to exit at the end of the tail pipe.

Gary, he talked to Mercruiser and they said that they have never tested the 500 EFI with silent choice and they don't reccomend it. The heads will be back this week and he should be running mid week. He ordered new tail pipes from CMI and the only thing that he is not going to do right now is take the Y-Pipe out of the boat because it would require hauling the boat out of the water. We are still trying to come up with a way to block off the Y-Pipe in the boat. We were thinking of using what plumblers use to ccover a pipe before they do an install, a 4" rubber pipe cover with two clamps? Any suggestions?

Donzi26zx,I've seen people block off the Y-pipes with rubber caps. It seems to work. It looks kind of funky,but it's a lot cheaper than pulling the motors.

Call Jeff Post at Corsa 440-891-0999 x125 (direct line).

I recall him talking about reversion w/ these motors. Thought he said Merc. initiated a cam change to fix the overlap/ reversion with this exhaust.