Wow! 6100 RPM

None of the two strokes develop much horsepower below 7000 RPM. A few hundred RPM makes a big difference. Recently I broke a 22 - 10 and the muffler. Replaced the muffler with a different type and used a 22 - 8 and the RPM was down 400 RPM. Performance was very poor.

A simple down an dirty test is to remove the muffler and check the RPM.

Someone might loan you a prop for ground testing.

Bill