Originally Posted by Wansfel
Yes, I found a Bultaco model/serial number list online. This is a model 18 by the serial number production number 711.
The engine is powerful with 43,5 - 42,5 hp at 7,500 rpm. The ignition is a special Femsa unit with two plugs, one near the exhaust (warmer unit) and one behind (colder unit).
It's said the power and is more on-off like.
l personal prefer more the slow going Sherpas with much torque.