I have a 1984 Johnston 90h.p. vro and have been given a 1976 200hp Evinrude service manual. Apart from the obvious like 6 pots instead of 4 and butterfly chokes instead gas spray,premix as apposed to vro etc. the manual appears to very similar to my motor. Would the wiring diagrams for the charging, trim tilt etc. be applicable to mine, also what is the difference between an Evinrude and a Johnston of a similar year and horsepower.Thanks