Home › Forum › Ask A Member › 71/2hp evinrude › Re: 71/2hp evinrude
If you are lucky you may have a blown head gasket. Since both are way down in compression that may be the case.
Jerry gave you some sound advice on oil ratios. Do not deviate from that.
Also time to check the water pump impeller and also possibly the exhaust cover gasket.
I believe for that engine the powerhead will have to come off to change the water pump impeller or complete pump anyway. That will give you easy access for the gasket inspections.
Rule of thumb on when it is time to replace the water pump housing is that if you can catch a fingernail in a groove inside either the pump housing or the lower plate…..replace the complete pump. Lots cheaper than a powerhead with parts that are almost made of "unobtainium" these days.