RBake

I have a 454 in my Scarab 29 with the vacuum type silent choice. When I want loud, the small compressor pumps up and the solenoids close fine. But, when I want it quiet, I can hear both solenoids release the air pressure, but the starboard side doesn't open. I've tried to oil it and it works back and forth by hand fine.

Has anyone experienced this, is it bad to run one side loud and the other quiet?? Does it need to be replaced or is a spring or something inside bad??

Any help would be appreciated.

Doller Offshore

there is a oil seal and a bushing in that swivel area those probably need to be replaced,clean up the shaft also

chubbytug

I had the same situation on my 23 Nova with 454. I took the Y pipes out and found that the butterflies inside were the problem. They were sticking because of wear/carbon buildup. I used a scotch brite pad and some 220 grit paper to clean the insides up and they work fine now.

RBake

Is ther an electric replacement solenoid that will simply bolt in place of the vacuum operated one??

Tinkerer

the first thing to try is put a little dish soap inside the air fitting and then work it back and forth ( NEVER USE OIL )
I used oil before I talked to someone that knew what to do. I ended up replacing all 4 of mine.

US1 Fountain

If one side is switching and the other is not, then you know it is venting the air pressure fine. So something is binding just a bit in the linkage, it doesn't take much for them to hang up. Or as someone else mentioned, just enough of exhaust build up inside the divetor valve that it is allowing the butterfly stick where it contacts the inside of the valve. I assume that you can just touch it with your hand when it is 'stuck' and it will flip. I had same thing and fixed it by loosening the 2 cyl. mounting screws a little and just move the bracket just a hair until it no longer binds.

BTW, you have Mercury's 'silent choice', so the "solenoids" you are referring to are actually spring return air cylinders. It works off air pressure, not vaccum. There is only 1 solenoid on that system and it is on the pump unit itself. It will vent the air line when asked to do so. The cylinders are not repairable when they go bad.

Hudson

My 454 has "captains call"exhaust. When I switch to "loud", both cylinders activate and open the butterfly valves, but after a short time, the port exhaust goes back to "silent" all by itself.

Someone said the cylinders are not repairable. I was hoping there would be a seal or o-ring to replace in there. Are they really not repairable? Is "Captains Call" the same as "Silent Choice?"

chubbytug

Yes they are the same, and no they are not repairable, the air cylinders are sealed and from what I have found they are pretty expensive to replace.

US1 Fountain

I bought a pair of air cylinders from McMaster Carr. Same size and mount, but they are air return instead of spring return. In other words, air pressure will hold them open instead of closed, or vise versa. I forget. Just have to switch the 2 leads on the switch if you would want the switch to operate same as before. I think they were only $20 each. Never did install them as that turned out not to be the prioblem. Have since sold that boat.

Hudson, that is a common condition when the relief valve gets dirty and does not seal 100%. Once the air leaks down enough, the smoothest operating divertor valve will switch back to quiet mode. Since the other one is not also switching, it may be a bit sticky wereas the gradual air leak doesn't switch it like the sudden venting when they are switched by the driver. The relief valve is at the air pump and is easy to clean. May also be a leak at any of the connections. Soapy water sprayed on all connections will show the leak.