I have a 1993 Larson 200 SEI with a Mercruiser GM V-8 305 CID (5.0L) OD847934 MCM Alpha Model engine and alpha one gen II std rotation OD469884 and above stern drive unit. When going at 1000 RPM's or less the temp goes up to 250F in 5 min. or so and then the engine shuts down. When cooled down the engine starts and if you go at least 1500 to 2000 RPM's the temp drops down to normal and runs below 250F even at top speed. All inlets are clear and installed a new stern drive pump kit 47-43026K06. Same problem still occurs. Any ideas on what the problem may be and what to try next?
