I have a 93 (i think) Evinrude 28 hp. A starting issue has developed. In a nutshell if the battery is not fully charged the motor wont fire. It will crank over like normal with the battery that is in the boat but if that battery is not fully charged it wont fire up. If i throw a freshly charged battery on it via jumper cables to the normal battery it starts right up. Could this be an issue with the coil not working correctly with slightly depleted battery voltage? There is no difference in the RPM it is cranking when on the original battery vs it being jumped. Hopefully someone has an idea as this has me stumped...

