Change the transmission chain

Hello boys;i have to make a modification on my bike and I would like the opinion of the connoisseurs.
My bike ea a Qingqi QMR200 and i want to change the transmission chain:Today tine string 428 and a ratio of 48/15.
you think put chain 520;but i need alluden with the relationship to not change the performance of the machine

You need to change sprockets as a 520 chain is bigger. So i pretty sure you measure OD of your sprockets to keep the same ratio.