FYI,adding oil to the gas and running the injector could be the reason it blew up..to much oil is just as bad as no oil at all..what did you mix the tank of gas at?

 

ive learned that lesson before on one of my old snowmobiles
i feel your pain slreno two days after i bought my quad it blew up but it was kind of my fault so i didnt hassle the seller because i test rode it and everything work when i bought it. Sounds like you might have a case but it probaly isnt worth all the agravation it will be cheaper to just rebuild it yourself or take it to a shop.

make sure when you get it bored that the machine shop knows what they are doing and any shop that will bore it out with out the piston you are putting in it is a sure sign that they dont know what they are doing the whole thing should only cost about $160 if you do the work yourself