2000 Evinrude 50Hp Electronic fuel injected the check engine lights comes on.

[ajohnson035]

I have a 2000 evinrude 50hp. I hook it up to the garden hose with ears and run it for 15 mins and the check engine light comes on. I had a new water pump impeller installed and the thermostat is opening and closing properly. However the cover that goes over the thermostat gets very hot you can only hold your hand on it for about 3-5 secs or it will burn you. I tried running it without the thermostat and the check engine light comes on immediately. However with the thermostat installed the light comes on after it has been idling on garden hose for about 15mins. What do I do next. My mechanic did not have the adapter for my motor to hook it up to the computer. Thanks for your help.