Thanks for the info guys. I was thinking the exhaust may be the issue and the air in the hoses. That is the bummer with having to mount thru the transom. The intake is right near one of the exhaust pipes.
What is it about the check valve that won't allow the air to go through?
Chptrill, I may need to get two from you.
The emptying works great on the system.
Here are some more pictures of the finished product.



What is it about the check valve that won't allow the air to go through?
Chptrill, I may need to get two from you.
The emptying works great on the system.
Here are some more pictures of the finished product.




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