dereknkathy

i just scared up a set of OEM merc exhaust diverters. is silent choice merc's name for them? or is that one of the aftermarket terms? anyway, they have the air pistons on them. do they have to have air pressure to hold open all the time? what PSI do they need to open them? would it be possible to use engine vacuum to hold them shut? (i know i would need different actuators) are these particularly valuable? i see them for sale on ebay for a buncha money, but sometimes people put stuff up there to see if there is an idiot willing to pay 5 times what something is worth. thanks. derek.

Gimme Fuel

Ive always wondered if I could go to an industrial automation store and just find nice lil weatherproof electric solenoids to get rid of air system. I am going to do some research for my mufflers I will be installing. Anyone else find something like that that has worked?

CDShack

I have a set of Gaffig that I haven't used in years, but they have a small pump. Default (no air) is open. Hit the switch, the pump comes on and builds pressure/vacuum and they close. hit switch again and relief valve opens and they open and it's back to default. likely the same principle.

Budman II

I used to run a set of the Silent Choice on my boat when it had the Merc stock exhaust. And yes, they use a small 12V compressor and plastic lines very similar to the ice maker water line to actuate them. On mine, the default position was closed - thru prop. The air pressure would hold the butterflies open. There was a momentary 3-way switch on the dash that controlled a relay to run the pump. When you hit the "thru-prop" position it opened a solenoid valve to purge the air and release it. It also had a pressure release valve to keep from over-pressurizing it. Many people who have problems with these leaking down actually have a little bit of dirt get stuck in the relief valve. Mine worked almost flawlessly for ten years, but I know others have not been so lucky.

You could probably build your own pump using one of the little 12V compressors like they sell at Harbor freight. You would have to do the wiring, set up the solenoid release valve and the pressure relief valve. Probably easier to find a complete setup somewhere. Try the Swap Shop section.

And for the record, Merc called their air actuated version "Silent Choice". I think they went with air so that the electronics could be separated from gas fumes in the bilge. Using air to operate the diverters removes another possible explosion source. Corsa had a version that used an electric actuator that they called "Captains Call". I think Imco also had one that used a screw type actuator instead of a lever.

dereknkathy

ok, they need 30 psi. stuff is cheap unless it says mercruiser on it. I can buy whole setup on ebay for 900 bucks. or stuff from ebay for about 30... I think I am gonna try this. also I can see reasoning for one less electrical thing especially right at end of everything where you have hot salt water that really loves to conduct electricity.

VoodooRob

Just a thought, I do not have experience with the air system diverters. In the motorcycle industry we use small air compressors, quick connect fittings, small air tanks, etc for suspension air ride. I would be willing to bet many of the components would crossover. Maybe add an air tank, so your compressor will hardly run and air would be "on demand".

dereknkathy

u run compressor for 3 to 10 seconds while it fills pistons and opens thru hull. then pressure holds open till u hit valve to release pressure. sounds like the cheapest walmart compressor will do the job...until it gets salt water on it!!

mike tkach

just remember you get what you pay for,or less.

92nsx

I use a toggle switch to activate mine

KEPP

PM me if you have any questions.

http://www.keitheickert.com/c-461-hardin-marine.aspx