Do they still make 2 stroke dirt bikes?

Answer 1

This response will address race dirt bikes and ignore the entry level air cooled 4-strokes such as the TTR's, CRFxxxF's, KLX's, etc. The 4-strokes tend to be a little better on fuel and pollute less as a rule. Gone are the days of 4-strokes lasting forever and being bullet proof. The race 2-strokes and 4-strokes enjoy a similar reliability history with the 250's being somewhat worse due to the high RPM's they run. 4-stroke power delivery is more desirable by some groups due to the low end torque and smoothness. There is still a small weight penalty (5-10 lbs in many cases) with 4-strokes. Probably universally the most undesirable aspects of the 4-stroke race dirt bikes is the fact that 1) they can be very difficult to start, 2) parts and accessories typically cost 2X to 3X as much (rebuild parts, after market exhaust, etc.) as 2-strokes. 3) the horrific costs associated with valve jobs (titanium) and the frequency some brands will require this repair. Why did the 4-strokes all but replace the 2-strokes in Motocross? The AMA changed the class rules such that a rider will get the most power from 4-stroke in a given class. It is rumored that the AMA sold out to the EPA. To put it another way, the power of a 2-stroke 125 does NOT equal that of a 4-stroke 250. The power of a 2-stroke 250 does NOT equal that of a 4-stroke 450. The AMA has pretended it does in an effort to kill the 2-stroke. The 2-stroke is alive and well (and often preferred) in the freestyle MX sect as well as the off-road market (GNCC, hare scrambles, enduros, etc). These 2-stroke bikes are plentiful among the European mfr's such as KTM, Husqvarna, Gas Gas, etc.). Yamaha's YZ250 is still available as well.