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There has been a lot of discussion about the real power available from the real wheel
of XS650. And surely the discussion continues further...
Below illustrated are two power & torque curves from the different sources.
Both are done for the 1977 XS650D model.
The first one tells that the peak power is 45.61 hp at 7500 rpm. The second one 36.3 hp at 7000 rpm.
The maximum torque numbers are 36.16 / 6000 rpm and about 40 / 5500 rpm (foot pounds).
Quite a difference between measurements! But at least the torque measurements might not be
compatible at all.