Well, its not in a Z but you guys are 'experts' so I 'll give it a shot. I got this old tractor I'm restoring, and its stuck. Been stuck. Tried letting oil soaked in the cylinders. Tried pounding with a block and hammer on the pistons, tried Coke, tried water(some guy said this would work) now what should I try? Don't want to pull the crank, and pistons and sleeves will be replaced. Any ideas? Thanks.