I have a Kitfox model IV with a 582 engine. It looses about a thousand rpm's
when taking off. After I apply full power rpm's come up to 6000 to 6400 as
soon aircraft starts moving foward rpm's drop to 5000.

I have checked compression good on both cyl. (120lb). checked carburetors.
Replaced all fuel lines. rebuilt pulse fuel pump. Same condition with electric fuel pump on or off.

Any advice would be appreciated.

Norton Sudduth