You need to go to http://www.kohlereng...als/landing.htm and download a manual before you do anything else. Most of your questions will be answered in that manual.
Yes, changing the timing can make the knock a little less noticeable, but I think you have other problems. If changing the timing reduces the knock, then you probably have an out-of-round crankshaft journal. Changing the timing is just changing the point where the connecting rod is slamming down on the crank. It is not fixing the problem.
There is a link to a site where the "static timing" procedure is described.
For a complete description of this technique with pictures, please refer to the "HOW TO" section on a web site by Matt Gonitzke, http://mgonitzke.net16.net/
Before you do serious damage to the engine, I think you need to have the crankshaft journal and inside diameter of the rod measured by a reputable machine shop.