Hi Thank you for looking at this. I messed up. Got engine super hot. Seized rings top right cylinder 0 psi. All other cylinders 90 to 100 psi. 1988 ProV 150 I took head off and see some slight metal transfer to the cylinder wall. took carbs off and manifold off thinking I can take piston out. Only seem to have access to one nut on the rod. I was hoping to take the piston out and replace. Am I looking at a total rebuild? Any thoughts?