I've owned and modified multiple TTR125s, and I've tried everything from simple jetting and suspension changes to a Mikuni VM24 carb swap, frame cradle and engine performance mods. If you're an adult or aggressive rider, I wouldn't start by adding more horsepower. I'd upgrade the suspension first. The stock TTR125 engine is actually pretty good …
Ttr125
The XR100 vs TTR125 is a popular battle among the best beginner bikes. Why? Because they are easy to ride, have a clutch, and require very little maintenance compared to a motocross bike. Change the oil and filter regularly, as well as lubing the chain, and these trail bikes will last virtually forever. So the …