Hi,got a 20 hp evinrude 1985,was has not been used for the last 8 years.Changed the impeller,and after a few pulls on the rope it started!!.But then it was a sputtering telltale flow of water.When opening the cylinderhead,you can see why 
.Now when removing the bolts,one broke off,so i have to remove the rest of the head.My question is,can i do that quite easily and remove the big bolts,or do i have to dissamble the complete powerhead ?
.Now when removing the bolts,one broke off,so i have to remove the rest of the head.My question is,can i do that quite easily and remove the big bolts,or do i have to dissamble the complete powerhead ?