What is the max bore for the 250r? I melted the piston in my current bike and it reads 0.75 how much cylinder wall do I have left till it is too thin? Thanks Matt
i think you could go 100 over on the 87-89 and 125 over on the 86. i may be wrong on that, but at 75 over either way you should still have a bore or two.
both the 85-86 and the 87-89 can safely be bored up to 14 over or 69.5. based on piston availability, the 85-86 can go up to a 69.5mm(14 over bores) and the 87-89 can go up to a 68mm(8 over bores).
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