We have a Yanmar 4JHE 54hp engine on our 2006 H41DS. As long as I have owned the the boat the exhaust has "spit" out water while running. Not a steady flow but an occasional rush. I have checked and changed the impeller regularly and never found a problem. I have always thought it was normal and never questioned it but I saw a post on another forum that says this is indicative of a exhaust problem. Is that the case? Your thoughts please!