If the pistons seized, then you probably have damge to the cylinders, and that is the expensive part. About $700 each. Plus pistons rings and gaskets I see at least $1,700. If the crank is bad add another $800+. If the rear wheel locked up instantly you may have damaged the rods/crank, or if debris has found its way into the crank case. $3,500 is not totally unrealistic for a dealer to fix. Sometimes the cylinders can be fixed for about $150 each, so the cheapest your looking at is about $700 if all goes well and you do the work yourself.
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james
Its not how fast you go...Its how you go fast.
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