I have a 2006 volvo gi-f i/o serial#4012191678 fresh water cooled. DP-s drive. Over 3600 rpm goes into limp mode. Started doing this the middle of last season. No problems lower speed. If I pull the exhaust sensors the engine will run. Replaced the sensors, did not correct the problem. Engine temp seems fine. Oil pressure seems fine. Highest heat is on the starboard riser, 210 degrees after high speed. Is this normal temp? Why would this be hot and the engine OK? Back flushed everything on the raw water intake, flows through OK. Checked impeller (new last year), looks good. Inspected heat exchanger, looks good. Had the risers and manifolds off, not much rust, everything looks clear. I use neutra salt system every shutdown. Thinking of replacing engine temp sensor and thermostat, but it seems to me, since engine temp is OK, that would not help. Could it be a timing issue? I know I should have a scan done, but everyone is busy in my area and I'm trying to make headway on this if I can. Would appreciate any ideas.
