Quote Originally Posted by Aaron

My father has a lathe, if rusty pistons is my problem too is it much of a job? Do you have any tips based on hindsight?
No, a straight foward operation. Turned the outside and faced the end, bored the centre, all on one setup to make sure the end (what touches the brake pads) and the outside were all square. Cut off, turned the inside face flat and put a chamfer on the edge. I did 4 in a couple of hours or less, so I had some for my spare calipers.
Make sure the outside is turned smooth so it doesn't stuff the seals - common sense really. If you need to, you might be able to match the seals at a brake place - the Yamaha seals matched a Falcon (?) seal, but the price was much the same as OEM Yamaha bits. Couldn't find any aftermarket seal kits for the LC at the time. The GSX250 should have seal kits available.

I got my stainless from Stainless Alloys, in Harris Road. Stainless is can be gummy and not very nice to turn, depending on the grade. I used 316, since that is what they had. Use a slow speed, high feed so it doesn't work harden, and cutting oil or coolant. Carbide tips may also help, although I just used standard HSS tool bits.
Geoff