I've got two of those engines and one is still pickled in the crate waiting for a future project .
I was told that the 6 hp rating was based on an elevated altitude of like 10,000 feet .
If you search on line for the 4a032 Continental or Teledyne engine and you can find a lot of information .
The carb is the weak link of the engine . It has a composite material type float in the carb that tends to swell up and stick with the ethanol gas used today . Most people swap it out with a regular brass type float.
Its also only got a 1/2 inch throat which restricts the performance .
There was an article online that I read where you can disassemble the carb , you can open it up to 5/8 if you have a drill press .
But you'll also have to enlarge one of the air passages to increase richness of the fuel mixture .
Its not that hard to make these mods , ( I did it on mine ) and it does increase HP output .
There easily capable of turning out up to 18 hp. and I've read with some machine work over 20 plus hp.
They are a super fast revving engine and power to weight is good . They only weigh about 75 lbs.
That engines been used in ultralight plane and those funny prop boats that they use in the Everglades ..... LOL
Do a Google search or youtube on 4a032 and you'll get a lot of hits .