717 engine making grinding noise. here is a video

[toddfw2003]

I had the engine rebuilt two months ago. This is my third outing and it died on me. at first it wouldnt turn over but now it does but it makes this zipping/grinding noise. Here is a video made of it


https://www.youtube.com/watch?v=cOtbW4atnfE&feature=youtu.be

 

[toddfw2003]

rotary valve?

 

[Mekanix]

Sounds like the rotary valve gear is stripped.