I have a 1974 135 Evinrude V 4 with no spark on any plugs. I took the sensor wire off of the power pack and grounded the sensor terminal of the pwer pack while cranking and got a spark. Does this mean that the timer base assembly is bad. Seems to me if you ground the sensor and the power pack fires the coil that the Power pack is good. Any suggestions as to which one is bad?