They will run (poorly) on it. Four stroke engines have a sump to hold the oil so none is needed in the fuel
My opinion, no. You have to mix gas for the two stroke, and two stokes are not as powerful.
A Kawasaki KX250F is a four-valve four-stroke single motocross motorcycle. It can be bought on the official Kawasaki website, which sells dirt bikes, motosport bikes, and motocross bikes.
It's found on all four stroke motocross bikes and it helps you start your engine when it heats up by changing the fuel/air mixture ratio.
Assuming you are referring to a street legal motorcycle (IE: Kawaski Vulcan, Ninja, etc.) these machines have four stroke engines. Dirt Bikes and such sometimes do not. Two-stroke engines generally use a fuel+oil mixture. (Such as a weed whacker) Four stroke engines generally have an oil sump. (Like a car)
no
Two strokes can accelerate faster but it depends on engine size
KTM!!!
no
Depends on the make and model of the bike. Some motocross bikes have 4 gears while most of the cross country thumpers are 5 or 6 speeds.
Brand wise, it is KTM. The make a wide varity of dirt bikes in both two and four strokes. They have everything from kid's bikes to enduro bikes to MX bike. They are by far the best.
A 2-stroke dirtbike will be powered by a 2-stroke engine and a 4-stroke dirtbike will be powered by a 4-stroke engine. For the same power, the 2-stroke will be a lighter bike. For the same weight, the 4-stroke will be a weaker/slower bike. The 2-stroke is likely to use more fuel and make more noise. The 4-stroke will run cleaner and quieter.
No only 2-stoke bikes have powerbands, the xr100 is a four stroke.