With help from a buddy up in Maple Leaf country, I was able to install a CDI/coil from a Polaris on to my modified 81' Invader 440 trial rider. The CDI has a more modern and improved ignition curve. My friend built a motor, dyno'd it, then installed the CDI and dyno'd again. While there weren't any gains to the peak HP, the shape of the curve was dramatically improved in the lower end and mid-range(which is great for a trail rider sled). I finished the install last night and took it for a ride. I noticed immediately that it started easier and idled better, so much so, I had to adjust the idle air screws and the idle screws. Throttle response also seems improved. I could definitely feel the improved mid-range RPM power as well. However I will need to make some clutching adjustments to take full advantage of the added performance. I'm planning to reduce the engagement RPM and increase the upshift which was exactly my goal going into this project.