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1982 Evinrude 7.5 HP shuts down when it reaches Operating temperature

S

steveP51

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Hello - I have a 1982 Evinrude 7.5 HP that overheated badly ,such that the Cylinder heads discolored . I changed the Impeller & Thermostat on it .The motor starts well ,runs well until it gets to operating temperatures ,then it dies suddenly . When it cools down it will restart easily . I suspect Electronic components were damaged in the previous overheat situation but what component(s) should be changed/replaced first ? Thanks for your help ,Steve
 
are you sure that your motor doesnt seize??? or try it whith out the thermostat .MAKE SURE THAT YOU CAN SEE WHATER COMMING OUT AN CHECK THE NEEDEL ON YOUR CARB IF YOUR NOT RUNNING TO LEAN ,TURN THE AIR SCREW ON THE CARB AN RELEAS IT 1 1/2. GIVE ME SOME NEWS
 
Was compression test done after the first overheat? What do the plugs look like after running? Is engine still running hot? Can hand be placed in telltale stream& held there? Let's make sure engine is running cooler than before. The stator assembly usually takes a hit first,look for melting goo from under flywheel. Test before buying with ohm meter as per shop manual.
 
Yes the motor is not seized as I can still pull the engine through without any extra resistance from normal amount . Water is exiting the tell tale water outlet just fine . I will try to get out on the lake this weekend to try the carb adjustment but it doesn't seem like that is the problem here . It just dies quickly .... Then when I let it cool ,it will start up great again ,run a short few minutes then cut out again .
 
No compression check was done as unfortunately I do not have a compression check gauge .The plugs were as follows : Top plug had some white residue on outside of the spark plug barrel ( the part that goes into the cylinder head ) . Bottom plug looked like a dirty black color all over . I have since changed both spark plugs for brand new ones. The motor starts fine ( as it did before ) , with a normal amount of compression resistance from the starter pull rope . The water outlet/Telltale stream water is coming out instantly since the impeller change ,and the water is cool enough to put your hand under it until the motor stops (which is a few minutes maximum ) . I did not see any GOO or melting residue under or near the flywheel . I don't have any manuals at all .This motor was bought new by my family in 1982 ,so we are trying to keep it around for the Great grandkids to use .It dies off so quickly that it makes me think that it is an ELECTRONICS problem. When it cools down it will start back up and repeat the whole process over again . I'm stumped but I'm mnot a good mechanic either so that's not saying much .
 
Hello - yes I believe that may be the case as well . If you have access to a manual ,would you be able to tell me what the COIL CHECK with an OHM meter should be for accept/reject the coils .....?
 
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