Quick update on our project.
We installed this setup last weekend and got fouled by a bad ground that wouldn't let the ski crank fast enough to fire the second plug. We replaced the ground and tried again and ran into the same issue.
We used my new timing light to check his cranking rpm and found it was only at 300 and that was with the plugs out. This system needs to see 400 RPM to fire the second so that explains that. Scott was doing all his wrenching late and never wanted to fire up the ski and risk pissing off his neighbors so he was settling for cranking the ski with the plugs out. We headed to his house yesterday at lunch, threaded in the plugs and it cranked right up, even with the battery at 50%.
As long as it can crank fast enough to fire the first plug, it should get enough kick from that to get over 400 and fire the second.