The Veno 5 will stop it just fine. Mine is on a DR (same as CRG) with Veno 5. If you lower the conection point on the brake pedal you’ll get more pedal throw and more pressure on the pads and it will stop as quickly or better than most shifters.
It takes some experimenting to make the whole kart work with that engine but it’s a hell of a ride. No 2 stroke can match the power band and torque of a CRF 450. With sprint track gearing if I’m not carfull I can pull the front wheels off the ground.
My times on a tight sprint track are better with the CRF than they are with a good stock Honda. You have to drive it diffrently. With the stock honda you can accelerate hard at the apex. With the CRF you need to accelerate moderatly at the apex then hard coming out so you don’t break the rear free. On a big track no 125 anything will touch it.
I drove a CR 250 one time. There’s a lot more vibration the power band is much shorter and It’s harder to control. I didn’t have time to really learn it but I think the CRF is faster on a sprint track because it’s so much easier to control.
Brian