As noted by Andrew, MerCruiser has taken over service support for the QSD series. If you call the MerCruiser technical support office they can reference you to a certified service center in your area. We are fortunate in that our marina is full service and they are a certified service center for MerCruiser. Our R25 classic was purchased new in early 2010 and have yet to experience a mechanical problem other than a minor issue with a bad neutral safety switch - 15 min fix. What I found early on when the Cummins folks were swapping out the ECM for a factory service bulletin (cold start) was the interface cable needed to connect the computer was a very, very long peg in the process - no one seemed to have them. I spoke with our service department they had the laptop - software - cable interface connector for the laptop, but no actual cable. What I ended up doing was getting the part number for the required special cable, found one on e-bay and purchased for less than $100. No more worries if the special cable is available! My apologies for the rambling reply but sometimes it helps to know potential issues for service.
