Motorcycle Safety & Driveability: Bike choice., horsepower advantage, cam chains

Question
Bill.  I am looking to buy a bike.  Dont know which way to go.  Motocross or offroad?  2stroke or 4stroke?  Do the offroad bikes require less maintenance?  I wont be racing but I dont want to be limited in speed or horsepower.  Ive ridden on and off through life on RM's and YZ's.  Ill be buying new, a 250, just dont know which way to go. Ive heard 2strokes might not be legal soon? And, whats a green sticker??  
Thx,
Jim

Answer
Jim,

Thanks for the questions.

My feeling on the 2-stroke/4-stroke issue is that the future belongs to 4-strokes. It used to be that 2-strokes had such a huge horsepower advantage that there was no real comparison. But 4-stroke design has matured and simplified to such a degree that it is now a viable, and to some riders, the "preferred" engine type. Modern 4-strokes make nearly the same pure horsepower as the same size 2-stroke, but typically have more "midgrange power" (torque) than a 2-stroke. Also, they are less peaky and tend to "hook-up" in the dirt better due to the longer duration between power pulses. 2-strokes were delveloped to run about as well as possible, but they will most likely be phased out of bikes larger than 50cc's as time foes on. 4-strokes continue to improve due to the R&D efforts of the major makers. Part of that is environmental pressures to be sure, but another part is the fact that 4-strokes just tend to be easier to live with and to ride fast.

As for maintenance, it's a trade off. 2-strokes don't have all the valve gear to mess with, but by design they require rebuilding much more often than 4-strokes. 4-strokes require you to mess with valves, cam chains and so forth, but they require rebuilding much less often and if you keep them tuned, they last longer. The design of 4-strokes continues to improve, so it's possible to tune your own bike to a high level of performance if you are willing to learn how, just like a 2-stroke. Between off-road and moto-x types, it really depends on how hard you punish the bike. More abuse means more wear, and that's going to mean more stuff breaking, no matter what you are riding.

As for a green sticker, we don't have that around here (Oregon), but it's probably the same as a Forest Pass or Off-Road permit. I'd check with the DMV, an off-road club or your state's DMV/RV website to get more info.

Finally, I'd suggest you try a 4-stroke 250. It'll have less bang on the top end, but it will have more power down low and in the midrange, and that can't be beat for climbing. If you really don't want to be "limited" in terms of speed or power, I'd look at a 450 4-stroke, especially from Yamaha. Huge power you'll probably never outgrow. But there's a lot to be said for the combination of power, light weight and agility of a 250. Whichever you choose, if you get a modern new bike, you will not be disappointed. They kick butt.

Ride safe, have fun,

Bill Roberson