My forklift has the older, cylindrical shaped ignition coil, with a 12 volt system. The coil was using an external resistor when I got the lift truck. It is now wired to get 12 volts when starting, and it fires up INSTANTLY. It then drops back to the resistor for running. However, after starting the engine with half choke and running for a couple of minutes, I push off the manual choke. As the engine warms up, you can hear cylinders "coming in" that weren't running properly before. A plug check found smutty plugs, but the engine runs relatively well after the "clearing out" occurs. The engine should not be over-choked, because I am just choking it enough to keep it running as well as possible, no black smoke exhausting, etc. I am wondering if the resistor is cutting back on the coil too much, affecting my spark after startup and during running. The coil has no markings. I am thinking about bypassing the resistor to see if things improve, but I obviously don't want to burn up the coil. Does anyone have any info on how to tell if a coil really NEEDS an external resistor? Any ohm readings I can take to tell if it's a coil that can be run without a resistor at 12 volts? Thanks for any helpful info.