I have a 2005 Catalina 320 and recently had the 50 hour checkup done. The mechanic was not able to adjust the valves as he could not remove the valve cover due to a bulkhead being in the way. I've spoken to the Yanmar dealer who supplies these engines to Catalina and have been told that the 3YM is not much different in size than the 3GM. I have a call in to Catalina to discuss and have contacted my dealer as well. The question I have is if anyone on this forum has experienced this problem and how it was resolved. Thanks!