Need advice...I bought my son a Kawasaki kx60...guy told me it's a 4 stroke So my son put straight gas and drove it for about a half tank and it stalled. I tryed everything can't get it started...getting spark and far as I can tell good compression.I opened the engine up...piston scored on sides...heavily pitted on top and part off ring looks melted to piston....now here's my question after kicking it about 100 tomes trying to start it locked...once opened and piston was free it was still locked,but a light turn on the nut broke it free and bottom end moves freely now....should I replace top end or is there a way to check bottom end before wasting my money...I have basic mechanic skill and common since...buy not experience....thanks
