whats the normal range for oil pressure in an 80? and how high would too high be for oil pressure? would it indicate a problem and if so would there be many possible culprits? my 40 and 80 tend to sit a little over the first mark line. the 60 I bought recently was sitting there until a few days ago when it shot up to between barely under the last mark and over the last mark. Ill be changing the oil shortly in it, wonder if old oil would cause it? anything to worry about?