John
Last year there were several girls that ran in the 50 comer class who were too old because of the very reasons you brought up, small and new at karting. I don’t think that kids should be pushed up in class just because they are at a particular age. Skill, size and motivations are much more important. Right now, the Comer 80 appears to be at a disadvantage in the CSC compared to the Briggs karts. I think we need to consider giving it a weight break.
If I had to go buy an engine for the Junior 1 class, I would look strongly at the Briggs Animal on gas. I ran the flat head on menthonal and while it is very fast, I was rebuilding engines every race weekend to keep them in top form. The valves just didn’t like bouncing off the head at 6,500 rpm 😀 If I had it to do all over, I would prefer the Comer 80 as 2 cycles are realtively cheap to run and they last forever. But running them heads up with the Briggs is tough.
Before you make a final decision, I would talk with the various track owners of the CSC. We allowed it last year in the Comer 50 class for a competitor to run who was “old” but it fit them perfectly.