What performance tricks do you do?

[Jrdragbike]

I'm just wondering what people will say, I think this thread will help a lot of people out, but what are some of the free tricks you guys do to make your motors faster and have more power, I cut off every other lip on my plastic flywheel fan, set my spark plug gap and drill out the jagged points on my intake and exhaust ports

 

[Newoldstock]

Compression.
the 14cc head is the most simple.
Add header and carb work later.