PowerSeal says they can Nikaseal coat cast in iron liners. send them cylinders, striped of valve rod tubes, and include pistons, and rings, and they will Nikaseal the cyinders to restore the ring end gap to whatever tolerance you want. for $220/per. My cylinders have so much wear I can feel it with my fingers. ring end gap is over 50% of spec. Bob Browder (?) said those production years, 77-78 could have have porosity in the casting, recomended not boring, and if a guy who could make money on the process says dont do it, I'll listen. Bike runs ok, 50 mpg on the highway, but like 110 psi. Anyone have experience with PowerSeal ?