I Bought a used ported tb off a guy, he said it was ported by Thunder Racing. My question is, when I hold it up to a light, I can see a good amount of light coming through at the bottom of the blade. I installed it at the same time as my cam, and its not tuned yet but still seems to idle ok around 800 rpms. Does the fact that I can see light mean that its over ported and trashed?

 

Not necessarily. Check the set screw. It may have the blade slightly open allowing light to shine through.