timing chain tensioner

Can someone give me a starting point on what i should do or check on my timing chain tensioner. I have a 1980 kz750, just bought cpl of months ago, rode fine, then one day, sounded like i was running on 2 cyclinders, had someone just take a quick look at it and he seemed to think that got play in timing chain. My question is there a way to check if that is the problem, where would i start without taking too much apart. And can i like reset the tensioner without pulling it off the motor. Thank You for someone to help me out.

You would know if it is the tensioner because the engine would rattle. A tensioner would not make you loose two of your cylinders.

should i pull the valve cover to see if lost one of the guides or can i reset the tensioner or should i pull it and put on a manual tensioner

I would mount a manual one anyways, but I think that you either have an ignition problem or a carburetor problem. What two cylinders drop out?

reset the tensioner according to the manual, I did mine and it was real easy after fully understanding what I was trying to accomplish.