Jimmy, by installing the 17 tooth sprocket you have geared the bike down, it will be a little slower but it will accelerate faster.
On the early models, Honda fitted smaller sprockets front and rear and had your problem from the outset.
They changed to larger sprockets to slow the chain speed down, this made the chains last longer, but if you don't look after it or use old master links or cheap chain the problem will not go away.
Sam.