The silent choice on my exhaust will not stay open. I pulled my boat out yesterday and ran my engines for a little bit.I opened the silent choice for the threw hull and they wouldn't stay open more 20 seconds before they would close up on there own. So I opened them again and they closed again. What is causing this problem.

Assuming you have the air actuated system then it's a vacuum leak. On mine it was the small valve that was attached to the pump. Took it apart and cleaned it. It will wold for days now.

I'll give that a try. Thank You.

This worked by the way mine was the something. It's a check valve on the pump. I pulled the plunger open and scrubbed it with a old tooth brush and it works fine now. Thanks for the info and the help.