I have a 1986 15 hp Evinrude . I have tried everything but it just won't fire. It has 80lbs. compression in both cylinders , new plugs , carb kit , fresh high test gas , 40-1 oil . I soaked the cylinders in liquid wrench for 2 days . How often does the power pack on these motors crap out ? Could it be weak coils ? This motor sat for about 2 yrs. before I got it . The last time it was used it would run for a little while and then cut out ( so I was told) Any ideas ?