tiba_karotsu
OVERREV TUNING
why don't polish exhaust port ?
exhaust ports on the 2stroke also function as a transfer port when it nears TDC, the returning pressure wave from the exhaust pipe forces the over scavenged air/fuel back into the cylinder, if the exhaust port is polished to a mirror like finish the fuel particles that make contact on that super smooth surface will stick & you'll be left with just air being pushed back into the cylinder creating a dangerous lean condition which could lead to detonation or pre-ignition, the result would be a destroyed piston.
this is also the reason why you also don't polish the transfer ports. on a 4stroke you can polish the exhaust port to a mirror finish but i find it to be very time consuming & not worth the perceived gains.