Hi Sam, I was wondering how you are doing. An easy check for the battery terminals is to turn on your headlights (engine off) and measure voltage directly on the lead battery terminals, then measure on the clamps or wires leading away from the battery. If the voltages are equal, the connections are good. If the voltage on the clamps is lower, then the connections need polishing. The higher amps of the starter motor will make the voltage drop even lower, and that could be effecting the ignition. Good idea to get a new battery. We probably should have started there. Check the simple things first.