When I was installing the belt on my 190E 16 vlave, I broke the "idler tension adjuster rod". What is the correct method of adjusting the belt tension? My understanding is that the pointer on the idler points to the left mark (small end of the incline) and you tighten the adjuster until the pointer points to the right hand mark (large end of the incline). I was about 75% there when the rod broke. I believe that the center bolt was loose. Any thoughts or assistance?

You did not have the center bolt loose enough. Or the tensioner was seized to the block.

I didn't break one, but I did strip one. I usually back out the center bolt quite a bit more than the manual calls for. Eventually, I pulled out the whole unit and cleaned it up and reassembled it. It helped for a short while and then the tensioner failed completely. It has been my experience that adjustment troubles can be a precursor to tensioner problems.