Still overheating

[ratkinson]

Please help! My 25hp 1970 johnson is reading as high as 200'F on the powerhead after running WOT. I checked the stat and impeller and they look fine. I pulled the plugs, no water. What could be the problem. Water is coming out of the water outlet...splutter and I blew air through the water cooling lines and got a good result. If anyone has any ideas please let me know. When I bought the engine the old stat was warped and in poor shape so I don't know if there is any internal damage. The engine runs well so I hope not.

 

[Xcusme]

Re: Still overheating

Looking fine and working fine can be two different things. Do you personally know the last time , for sure, when the impeller and t-stat were replaced ? If you don't know, nows the time. Replace them both and re-check temps. While you have the lower unit down, rig a garden hose to the water tube and check for good water flow. Have the thermostat out during the water flow test. Look for debris, old impeller pieces etc. Try forcing water into the thermostat opening too, to backflush the powerhed. Install new pump and t-stat and recheck. BTW, a water tube can pass air but have a hard time passing water.