Hello J.A.W>
You write:
"I'll add this actual test result, obtained by a skilled rider, who got into the mid 12 sec range on 1/4 mile acceleration,
& tucked in well for the top-end run.. (albeit it is an earlier, lesser-powered, if evidently well-tuned 1983 RZ 350)."
In the graphs generated by the RoadLoad program for the Yamaha RD350LC the total load (i.e. the weight of the "rider, passenger and luggage") has been taken as 170Kp (375lb).
With only a rider weighing 80Kp (175lb), the time for the 400m (~ 1/4 of a mile) drops at 12.36sec (speed at the end of the 400m distance: 164Km/h).
With only a rider weighing 50Kp (110lb), the time for the 400m (~ 1/4 of a mile) drops to 11,9sec with the exiting speed at 168Km/h.
Thanks
Manolis Pattakos