Buckwheat barbie hummingbird

What is a good replacement motor i can put into a 1983 fl250 honda odyssey for more power? - 1983 honda arrord hatch back

I have a 1983 Honda Odyssey FL250, who heads today, the restored original engine, but I've heard of people by different engines and mods are not powerful, though less secure in just what type they are used, and seeks proposals