u need to get some one to check the cylinders and pistons out to make sure eveything is the right size. u have already replaced the stuff in the botom side. so u might as well get the topside checked. u might need a bore or atleast a hone and probley new pistons.
my boy had a problem where his chain whould break every time the swing arm was miss aligned like a 16th of an inch.in the front. check it out. we used a string to check it.