Hi Chaps, I've removed the piston from my WR450 for inspection and have found it to be tapered. At the bottom it measures 95.00mm but at the top its 94.55mm. That's a 0.45mm (0.018") difference. Can anyone tell me if this is how it should be? The only reason I ask, is, the piston only looks lightly worn. If anyone has an unused WR piston that they could measure, to confirm, that would be very helpful. Best regards, Andy.