first, forgive me for my lack of knowledge about outboard motors. I bought a jon boat with a 7.5 hp ESKA motor, model #14209A. The previous owner told me the motor started easily, but quit running after a few minutes. Although the motor has a built in fuel tank, the owner was using an external tank. I was told to disconnect the external tank, and use the internal tank. The motor ran well for about 10 minutes, then quit. It smelled as if it might be overheating. Very little water is coming out the discharge.Does this motor have a water pump ? what is an impeller ? I see these for sale onthis site. Thanks so much for any help.