2-Stroke Engine Tuning
You may already know, there are loads of things you can do to your 125cc 2stroke engine. But that is not where I am going to start. It is very easy to spend big money on your engine and completely ruin your bike.
I did it to my old TZR. I had the power valve locked open to give about 28bhp, but the power band was only 1000rpm wide, and didn’t kick in until 10,000rpm. Below that there was no power at all. It made the bike completely un-ride able (although, once I got used to it and adjusted my riding style, I LOVED it ;)