Hi Carlos,
I am glad that I could help. Like all things, it is good to take one step at a time. Look at some of the pictures and get an idea on how to reduce the weight. Buy a light weight pitts muffler, such as B&B or Wackerengines.com. Use a resister plug, such as a RDJ7Y, available at auto parts store. Plug the hole in the cylinder. Get a short shaft 5/16x24 prop hub from Wacker and make a mounting plate from scrape aluminum. Use a 16x10 or 18x6 prop and test it. Later you can add an 11mm Walbro carb, which will have a 28 molded in the inlet on the venturi. If you don't know what you are doing timing changes can destroy the engine. You can also raise compression later.
I u sed to live in Moore in the seventies. Does 1204 north norman still exist, That was my old house? I think that it was taken out years ago in a tornado. It was close to I35.

Regards Dave