Lots of folks I see riding out on the street have improperly maintained chains.
The need for chain maintenance is one of those things that creeps up on you, before you know it you can hear your chain slapping around during gear changes - and you start to experience a strange delay when rolling on the throttle.
There are a couple of things to consider when evaluating your chain health.
First, the chain should have no more than about 1 inch of free movement - literally grab your chain and pull it up and down perpendicular to the road surface. If it moves too much up and down - time to tighten it.
The bike I owned previous to my Ninja ZX7R was a Yamaha XV250 Virago. It was a fun little bike.
Its previous owner didn't pay attention to chain tension - and the evidence was on the rear hub that she spun it off at some point during riding.
I don't know about you but I expect that losing a chain while riding down the highway is a bit too much adrenaline for anyone.
All chains can be adjusted by simply loosening the back wheel and moving it slightly backwards. All chains stretch as a normal part of their wear and tear. If your wheel is already all the way back in its adjustment range... time for a new chain. that means it has streched to its tolerance and is expired. Expect a $100-$200 bill for a new chain and the cost to have a technician install it.
in the old days they made chains with master links which could be pried loose with pliers and a flat screw driver. Not anymore.
With today's DOT standards you need a specialized tool for installing the master link in modern day chains. like I said, have an expert install it.
Second, keep the chain lubricated. There is no excuse for a dry chain. lube is cheap. use it.
When chains are dry they wear out fast, and rust easily.
Ask anyone who ever stored their bike for the winter with a dry chain - In the spring its corroded, stiff and always needs lube if not replacing altogether.
A chain is a vital part of your bike. Take care of it.