Hi Ken, Im new to this world.  I see your in CT, and you seem like the man to talk to about these engines.  I recently purchased an 02 blaster for my son and the thing came with the engine out of it.  Missing the Piston, and in 3 pieces.  I was going to attempt to reassemble, but Im not sure where to start.  Im mechinically inclined, and have the tools, but I really dont want to screw this thing up.  I was told it just needed a new piston, but  I was also told it was a big bore, Im not sure how to find out what size piston to get, and I was told not to mess with the bottom end, but im a little nervous about rebuilding only part of the motor.  Im in CT, ive called a few places but the labor seems pricey, even without the parts,  Is this something I should try myself or should I have it done by a pro?  Do you do engine rebuilds? Any suggestions?  thanks