What 50cc cylinder for a Yamaha Aerox?

I brought the bike and found out it has a cheap cylinder on it and this is causing worse performance. As i dont have enough money for an original yamaha one i was wondering if the doppler and airsal aluminum 50cc are any good? If not are there any other good makes out there?

 

If you can afford put the polini one on there
It will go very well

 

Ive got the Polini Race 50 bore and head, pretty quick i must say

I do have a Standard Aerox 50 bore , piston, head, needs gaskets
no damage etc, inbox me

 

i ordered the malossi 50 its abit cheaper

 

70kit? Why the hell not just get a 70kit?

What a waste of money buying a 50kit..