Step 1: Draw pictures.
Step 2: Buy steel/engine.
Step 3: Shape steel to look like your picture.
Step 4: Equip kart with engine.
Step 5: Enjoy your kart.
Seriously though, just browse the forums, see what others have done in the project log section. Do you have experience with welding/engine repair? Do you have tools available to undertake such a project?
Welcome to the forums, I hope you get a good experience here.
I r happy with this post. RLY.