help with 2 questions

[donthraen]

#1 how do the rings face in chainsaw it doesn't have stop pins in the groove #2 both the inlet and exhaust ports are oval shaped with 3 holes will it help,hurt or do nothing if I took and opened them up and made it oval without the howells in it

 

[oscar4883]

Probably get some answers if you posted in the chainsaw section. Every piston I have seen for a saw has pins to locate the ring ends. There is quite a bit involved in doing any work to the ports also.