I bought a replacement rotor for an SS30 trimmer. It doesn't look correct - it's about a half inch taller and at least a quarter inch smaller in diameter. I saw another post with about the same question, but no response. I didn't want to install it thinking I may need to return it. It sort of looks like the height might work out (but the other post said it interfered with the housing). And, regardless of the height issue, I question whether the smaller diameter will allow it to create an ignition spark through the magneto due to the wider gap between the magneto and the rotor. Any thoughts? Thanks for any help.