Piston won’t go up and down

[theguy2024]

I just put my bike back together and upon taking it out for a spin, when I released the clutch it seemed like the whole thing seized up and the back wheel wouldn’t move. It took a lot of force to just get it to turn over even once. What I noticed is that when I take the head off, or take the spark plug out, it cycles up and down just fine! The second I tighten the head bolts and create a seal, it acts like it’s seized up. Is this a compression issue?

what’s going on here?

 

[theguy2024]

Update: seems the engine has exploded

 

[Greg58]

From the locations of the holes it looks like you broke the rod, It will be interesting to see if you take it apart.

 

[Larry Trotter]

We’re you missing any nuts, bolts or Washers after you put it back together?

 

[Mossy]

I'm thinking of getting a few YD100 cranks.... Some con rods for 38mm there the heavier thicker rod....