So many ask the question of how to build an aircraft that a light sport rated pilot can fly.

Here is the answer to one typical speed question:

The speed of your completed airplane is dictated by it's overall configuration, not the engine. While it is true that Viking would like to show you how fast it could go, it is not true that you will automatically have this speed if you need to comply with a lesser speed.

The pitch of your ground adjustable propeller will give you a range of 10-20 mph one way or the other, depending on if it is set for cruise or climb.

The graph shown as the performance of the 130 is exactly that, a graph showing the performance of the engine at different outputs. You, being the "Manufacturer" of your home-built aircraft can set the power level to whatever you want / need. Again, you can do this simply by adding / subtracting pitch to the propeller.

Having a larger engine, then flying with high torque / high pitch / wide open throttle / GDI injection and low RPM is very efficient and quiet. Also makes for a long lasting engine.

Wheelpants / no wheelpants also adjust the speed 5 mph one way or the other as does larger / smaller wheels.