I pulled the starter on mine. It did not look like there is any way to remove the tensioner without moving the starter. I could be wrong. Are your valves out of adjustment? You can check them without having to mess with the tensioner. Compressing the tensioner back in is kind of a pain in the ass. Take your time and you'll get it. Also on mine it never looked like the timing marks line up %100 when you release the tensioner. They look off just a tiny little bit. Hope this helps. Maybe a few other people have some advise too!
It did not look like there is any way to remove the tensioner without moving the starter.
I think that's true. I've bought a Krieger manual tensioner which I've yet to fit, but the the instructions are clear, and say the s/m has to be unbolted. Not a deal, really.