1987 OMC Cobra 2.3L overheating

[Bruce K]

Hi, I have a 1987 Chris Craft with a OMC Cobra 2.3L, I have replaced the impeller and the thermostat and upper and lower exhaust hoses and riser gasket...but am still overheating quickly at cruising speed...HELP....I am new to boating and boat repairs,,

 

[makomark]

what did the exhaust elbow look like?

 

[Droid]

Fresh or salt water boat?

 

[Bruce K]

what did the exhaust elbow look like?

The aluminum one between the upper and lower hoses was pretty smokey, i wire brushed it.

 

[Bruce K]

Fresh or salt water boat?

Fresh water only

 

[Bruce K]

Update: i can run the boat on muffs, not much water coming out of prop...boat runs 9 minutes till thermostat opens, 12 minutes before it reaches 200°F and I shut it down