The first download is a small program which gives a graphical representation of the effect balance factors have on an engine. The engine configuration can be varied by changing the crankpin offset and the balance factor and shows in which direction the forces are concentrated through the engines 360 cycle. This is written in Javascript and if this is not installed on your computer it will not work. If you need to install Java it can be downloaded from the following website.

Engine Vibration Model

You may also need to associate this .jar file type with the downloaded java program in folder options in windows explorer.

If you can't follow this get a mate who is computer savvy to sort it for you.