Sportport. Drill or not to drill

[Deleted]

Hi. I'm drilling my cylinder (Honda X8R-S 50cc, cheap TNT cylinder). As you can see I had to weld this cylinder and modify lower gasket to make it fit correctly. What I'd liked to know is, can I drill this much off from my sportport and piston (pen shows the measure). Does it make any sense? Pros and cons. 

[190mech]

Yes,you can trim the cylinder there,it will flow much better..