Thom,
	thanks for the info on the speed restrictors.   I have a undone 
one on my '66 RHD Westy.  The '66's owners manual gives a top speed at 65MPH.
Once , passing a big truck on the last grade to Vegas from LA at 80mph
with a stock single port 1600,  I wondered if I was going too fast?  Had a 
Balanced counterweighted crank in the mild engine.  Gary Gibson