So mechanically speaking, it is very possible to make the CD-70 hit 150km/h+ , provided you make up for all that the engine requires to give the true performance of 124cc.
Did you look around to see if you could get these missing/required upgrades? (ignition advancer, better intake/exhaust, larger ports) ?
A few months back I saw that my uncle had an old and rusty kinghero - 70 (model 2006 I think) just staying idle in a dark room. I'm new to motorbikes so I decided that perhaps one could get it working. Then I have this distant cousin, who used to be a racer in Lahore and also ran his auto-shop specifically dedicated to modding and tweaking motorcycles.
He not only got this motorcycle working, he inspired me to turn it into a Jinn**
We had a complete overhaul and enginework done (though I have no idea about how much the bore x stroke was increased, we added a 100* type piston), new clutchplates and a larger frontsprocket:smaller backsprocket. It's funny, after doing this the bike would hit 40km/h+ on the first gear and 70km/h on the 2nd gear
I was really hoping to hit 120km/h+ and "break the needle", but I had to leave Pak at the time and didn't have enough time to complete the "running" for 500-600km..
Anyway it's not a rumour - alot of modded 70 machines (old Honda's especially) have been tweaked to break the needle on the speedometer, going past 120km/h. I once found a tweaked 70 from 1986 on olx.com.pk, where the seller said it had a topspeed of
So if a guy in Karachi can make an old cd-70 hit 135km/h (no weight reductions) then I'm sure a cg-125 can be made to hit 160-170km/h.
Is there any issue with engineoverheating? The CBR150 supposedly has liquidcooling.