Noob - Here for ideas/help for my sons Blaster

The only "sure" way to know if the cases are cracked is to split them. I've seen cracks that are so tiny that gas might weap thru and give a false indication. Anyway, we have repaired case halves that were missing dime size pieces and still seal, so there is hope.
 
I guess that will be my next step. Break it open !! Thanks for all the help so far guys, this is perfect !!!!
 
Well, I received another cylinder and head (package deal), but the boys mom turned into a raging biatch. So, she has the Blaster again (still torn apart) and says she will take it to her mechanic friend. I really hope not, cause this guy f'd up his go-cart a year ago. Oh well, guess I will be looking for a wheeler to keep at my house for him. If you guys here of something reasonably cheap that needs some work, let me know. I really appreciate all the help you guys have provided !!!