Cutting an old cylinder in half is an excellent learning tool.
This was a Yamaha Blaster cylinder cut apart as a learning tool:
From what I learned from it I stuffed it with several tubes of JBWeld epoxy in this manner (photoshopped):
Which in real life looked like this comparison:
The result was easier carb jet tuning because of fuel staying in suspension, wider powerband and of course, more power.
All gleaned from studying a sectioned cylinder.