Back to where we started. Our second practice and we are both still a little lost. New kart, new motor, new track. There was some stress when I asked Jason to push his kart until it spun. He wanted to keep it safe. To find the fast line in his own time, in his own way. There is a fine line between the pressure that we need to put on each other to keep making progress but keep things fun. Thankfully, we both kept our cool and focused on our jobs. So, he has been getting the laps in and I have struggling to figure out the right setup. We will have time later to watch the video see where his line was and if he needs to move it. Lately he has been watching the videos just for fun.
Jason is no longer in kid karts – he has moved up to the sportsman class. Sportsman class is for kids ages 7 to 12 and the rules are much less restrictive compared to kid karts. We can now change gearing to optimize the kart for the track and conditions. Over the winter I upgraded the Briggs & Stratton LO206jr motor by removing the 4100 rpm coil with a coil that’s now limited to 6100 rpm. I also replaced the very long kid kart with a shorter red slide. This will let more fuel and air in but not as much as the stock slide.
The red slide is the kicker. It causes the motor to perform very differently from the stock. The speed and power are on a different curve from stock so the normal gearing has not been working. Usually, the stock motor uses a 17 tooth gear on the clutch and a 68 tooth gear on the axle for a gear reduction of 4. It takes a bit of patience to find the gearing ratio that gets the most speed and acceleration. With the few sessions we have had, and the lack of experience, we have not been able to put different gears on and see how the kart performs. We have been all over the place with 17/55, 17/68, to 22/70, nothing was doing what I had hoped. With some more research and discussion with experts, I hope to have a better handle on it soon. This was our last chance to test gearing. Come race day it is going to be guess work. The first race of the 2013 season is April 6th at Concept Haulers Motor Speedway.