There isn't anything online as far as adjustments & maintenance. The owner's manual goes over this, but you'd have to see the pictures to follow along, as there is side-to-side and front-to-back adjustments, measuring the blade height.
The pics don't turn out well by copying, or I'd send you some (have tried before). Better off investing in a manual, you'll need it anyway. Last I checked service manuals were $100 and owners manuals were $43. There is a post that's callled "fast moving parts" that has manual prices.
Rattosh51
YT6800 S/N 821
St. Paul, MN