ok.. i heard that you can blow air into your speedo tubes that go to the water pickup and clear it out so the speedo registers the water going in... how do you do this and is it possible.. i use my boat on the calif delta and it can be a little mucky may have something in there.... any help woudl be nice.. not wanting to take it to dealer for this fix... i usually use the rpm guage anyways but it would be nice to have my dual speedo's working again,.