I recently purchased a package of used planes from a man. One of the planes was a .60 Piper Cub. When i first looked at it the prop was stiff but it was moveable, brought everything home and started working on loosening them up and now it seems to have only gotten stiffer. I have removed the glow plug and sprayed the system with wd-40 but still no luck. What do you all suggest i try next?