before you condemn the engine, is it possible that the valves are too tight? they are adjustable using shims of varying thickness and may be too tight. i had one at my shop with the same problem, the valves were too tight, try a leak down test and see if it is valves that are leaking, if so remove or loosen the cams and see if the cylinders that are lowest are better. i would not recommend the valve adjust or the cam removal as a do it yourself, it can be very involved. Ray
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