Lucas gonna be a moster speed rider,seems he always want's to learn,Ask's a million and 1 questions...best off all he pays attention & listens.
bigDaveF Never heard anyone wanting to change to 1st to 3rd................?
Unless you are red linning it in first which is why 3rd seems more comfatable for you,along with losing alot of excelleration out of second.
This seems such a shame you want to lose second,and very odd.....but as you said the 600 is monster power compared to the 125 cc The power band overlap maybe because you are letting the Rev's drop to quickly,maybe down to 5 OR 6 RPM Before you change gear for second.
Take on board the bikes going to seem agressive and fast,as for skipping a gear nothing really wrong with it,just such a shame you want to lose it.
Enjoy all the gears and don't miss any.
I think after you have gotten used to the bike a little more....enjoying riding it!!....... you may ask yourselve why would anyone want to change from 1st to 3rd.
Ride safe,and remember,respect your bike's power......it aint gonna respect you.