re Power - I'm not talking about a 250-2s vs a 250-4s. The motocross racing classes permit 125-2s vs 250-4s. This is what riding on the track is about - racing. For playbike and trail riding there are many more options when displacement is not about the rulebook (KDX220,WR250, or WR250f,WR450f, DRz400 if you wanna 4stk, etc.etc.)
quick response --> the total-cost-of-ownership discussion took place industry wide... oh... about 5-10 years ago.
Given the developments of the past 20-years a single cylinder 4-stroke engine of about twice the displacement can now be used competitively as a replacement for a 2-stroke motor in a motocross application. The rulebooks used to allow even larger displacement advantages to the 4-strokes. When the advantages of racing a 250-4stroke against a 125-2stroke, and 450-4s vs 250-2s came into play it pretty much changed the face of racing. With this class structure and the current 4-strokes, the 4-stroke is the faster bike on the track.
Since about 2005 all the factories run 4-strokes because that's what the manufacturers want to sell. KTM, Yamaha, TM and a few others still offer competitive 2-strokes to the public while others are all 4strk in anything but the 85cc-100cc categories. Honda dumped there CR85 for a CRf150 and the weight gain is acceptable to most.
Average owners discovered that there highly-tuned 4-stroke motocrossers were wearing out much quicker than they anticipated and that they were very expensive to maintain and rebuild over the long-term compared with 2-strokes. They (quite naturally) had much higher maintenance requirements than things like XR400s. There is nothing new or amazing about this.
Independent team owners like Kenny Roberts and Mitch Payton made it clear to the public long ago that it costs 3 to 4 times the amount of money to maintain these high-perf 4-stroke race bikes.
There's a large world economy with a hand in this game and like many things, politics helps feed you 4-strokes. They aren't going to recommend what they don't sell. And like politicians whatever they're selling is best for you. Flaws are denied and hidden, even in the face of reality. They have lots of marketing dollars to use for there benefit.
Motocross magazine editors played hush for awhile but began publishing stories about the costs of maintaining, rebuilding and modifying the current racing 4-strokes. This is all stuff that the majority of day-in-day-out race mechanics have known since day one and any decent home mechanic who races and keeps records already knows this too. People accept it because they like there bikes, and if they're having fun then it's all fair to them...
The bigger reality is the simplicity of the electric motor is already making huge gains so there's nothing that important to be concerned with here anyway in the long term- well, only capitalists, economists and the others who control your lives. But not even an earthquake could awaken this forum, nor decent AI-bots.
"Zounds! Zorched by Zarches, Spaceman Spiff's crippled craft crashes on planet Plootarg!"
For Sale: Ninja 600 with parts bike, needs minor work, $30, no title... (GEE THAT DOESNT RING ANY WARNING BELLS DOES IT?)