It's a dirt bike that uses a 2-stroke engine.
It would depend on what was wrong with the engine. More details are required.
Your bike is a 2 stroke. since you are mixing gas and oil together oil naturally blows out your tail pipe. if this is happening, then there is nothing wrong with your bike, unless it is a 4 stroke.
If your 2 stroke dirt bike starts to smoke really bad that means you have to much oil in the fuel or the wrong kind of oil. Or the pistons, oil rings or cylinders are badly worn.
Two strokes can accelerate faster but it depends on engine size
No we can't use 100cc 4 -stroke dirt bike race against 85cc dirt bikes.
4 stroke
depends 2 stroke of 4 stroke and racing bike or a trail bike
A 2 stroke.
depends on what you like 4 wheels or 2 so there is no real answer for your question its all about your taste, but my opinion is you cant go wrong with a good 2 stroke dirt bike :)
Haw fadt is a 65 2 stroke dirt bick
It's a two stroke