here is more information that i learned only by expirience and hope it will help other people to do projects on the small CR125R & HONDA dirtbikes in general:
the CRF 250X suspension (fork and rear shock) can fit to the CR easily with no changes and it gives great traction.
A kit is hard to get (especially in ISRAEL, here we hove nothing!!!) but you can fit front fork of new CRF's with no modes, except the caliper mount.
if you notice i took RMZ 450 2017 front fork and made sleeve that will make the fork fit the honda's front wheel.
calipers and triple clamps are the same.
the CR125 reacted great to the 144 kit with porting and now its awsome wood weapon.
if you like 6 speed transimtion (as i do) you can get 1997 complete gear and just bolt it on, its very easy (in case you open the lower engine offcors) all you need is the left case bearing to be replaced with the previous model.
ASV levers are'nt worth the money
CRF250L has a fuel tap\petcock that can be bolt on your small mx machine and then you have "reserve" option (it was necessary for me in the woods)
the mikouny carburator that comes on the original bike (39'mm bore) is peace of shit.
stop trying to jet it and just find a PWK 36mm air striker that will wake up your bike.
the radiator plastic can scratch the aluminum frame (known problem) make sure you put somthing to protect it.
A kit suspension is great for XC / WOOD / ENDURO / OFFROAD (whatever you call it across the sea) if it re'valved and re'sprang in respect.
well, thats it for now if i will remember anything new i'll post that here.
i am an Israeli guy so sorry for the spelling mistakes, if any one of ya'll have any question feel free to text me, i will give some advice.