Name:   Shortbus - Subject:   Mercruiser 4.3l Alpha 1 gen 2 overheat Date:   6/1/2018 3:40:53 PM

Was idling engine and starboard riser was getting too hot to touch, port cool.

Engine usually never over 150 was at 180-185.

Replaced 7 year old impeller.

Boat running at 35 mph temp 175.

Cold risers just after running long and fast.

Idle seems to bring engine temp down to 140-150 but starboard riser will get warmer than the other, maybe hot if idles long enough.

Have ordered riser gasket and thermostat kit.  All running fine after impeller but temp not as low as it was.

Any boat geniuses out there?