A large number of new EuroII 125/150 are unable to maxout and perform this is true it is also true for paiggios, deluxe, and GS to I remember last weekend I was with blue horn his GS is a A+ in engine, accelration and a neat clean Eye candy me being 80kg and BlueHorn being a Big Body man I wasnt expecting gs to cross 110 or some thing but to my amazement it was having hard time crossing 100 and to reach 100kmh it took around half a minute. (road was damn clear no rush and I had all the time noticing bikes responsiveness) then came the over head bridge of Fortress I throttled it to maximum and it reached on only 100 even on downhill
but on other hand I have seen GS in my own hands on double sawari going to 120kmh it was a 2004 model .... the only thing which I always notice is that if bike is going and increasing RPM that means its pushing but if its RPM needles stop bike stops getting more speed immediately ..
to date in stock I saw Hans deluxe making it to complete its RPM(4th gear only) then I had a friend in sabazar his simple 125 completes its RPM (and touches 105+)
these all bikes can really do 110+kmh when in healthy engine and what it really need is a rider and proper rich fuel tuning.
As a rider we never felt need of a GPS certificate to approve, because even one rip of the meter I can tell you I am on 120 from the air banging on my chest and the speed of road grains felt under my tyre.
And I am sure most old riders can also tell that too ...