250Fs Killed the Two-Stroke Star - Feature Review - Dirt Rider Magazine

Dear Dirt Rider,Of course you (and everyone else for that matter) know that the four-stroke motocrossers are taking over the two-strokes, especially in the 125 class. I don't think I saw a single 125 two-stroke racing at the Qualcomm Stadium Supercross last February, and there's probably not going to be a single 125 this year, either. I have heard so many rumors that motorcycle manufactures will stop making 125s within the next 5 years I am starting to believe it. I have a 1995 KX125 and I absolutely love it and I would never trade it in for a 250F.What are your staff's opinions about the ending of 125s? Do you really think motorcycle manufacturers will stop making 125s? And will your magazine still have coverage on 125s? Will you do the 2006 125 MX shootout? Thanks for having such a great magazine.Long Live 125 Two-strokes!Brian Melzer
Carlsbad CA

Brian,The fate of two-strokes is a long-standing debate, one that has aroused a lot of attention among both industry and enthusiasts. But while many riders—you included—are starting to believe in 125cc extinction, the reality is that the small bore two-stroke is far from dead. I'll try to explain why some people think so.The average cost for a 2006 250 four-stroke is around $6000. The price range for a 2006 125cc two-stroke sits between $5000 and $5400, roughly. For demonstration purposes, let's suppose that you have enough money for a new bike and—being the die-hard two-stroker that you sound like—you pick the 2006 125. Let's say the first thing you do is remove the air filter and go ride. The motor would quickly come to a screeching halt, but it wouldn't throw parts or break your cases. To fix this, we'll say you need a piston, head, cylinder, rings, head gasket and a pin bearing. According to Yamaha of Troy's web site, the parts would run you $973 for a 2004 YZ125 or $687 for a 2004 Honda CR125R. On the other hand, you go with the 250F, promptly rip out the air filter and go for a moto, resulting in an explosion that leaves you needing all of the same parts plus valves. Again, according to the YoT web site, a 2004 Honda CRF250R will run you $1076, and the 2004 Yamaha YZ250F would be $1511 for the same parts. In both cases, you have blown up your engine and re-built it for considerably different amounts of money. My point? The two-stroke is cheaper to fix, and you are more likely to do the work yourself.Point two: Modifications. Back to our old scenario, you buy a KTM 250 SXF for $6600, and install a $700 exhaust system for a grand total of $7300 into the bike. On the other hand, you purchase a $5400 KTM 125 SX and modify it to the newly legal amateur national size of 144cc, for the price of $1300, making this a $6700 bike. So, this leaves you with either a 250F with a pipe on it, or what some would call a competitive 144cc and $600 in your pocket—enough for a nice set of clamps or a stack of new tires. But if you do choose to go with the 250F and want to get the engine done, you can go ahead and send it to a modification company for a half hour on the mill and another hour of handiwork, a solid $499 according to most businesses. However, many casual trail riders don't care too much about having the latest, greatest mods—they just want to go ride. In this case, they are saving a bundle by going with a two-stroke.At this point, I think most four-stroke fans would argue that the 250F may be more expensive to modify, but it is cheaper to maintain. According to the prices of each, they are about equal. It breaks down like this: The Honda manual says that you should inspect a four-stroke piston every 17-20 hours, meaning that in the real world the bike will run great until it decides to go. A two-stroke piston will last at least that long for most riders, but you will lose some performance towards the end of each piston's life. For the 125cc, let's say that you throw in three $100 top ends a year... that's $300 without labor. Now, an equal number of 250F top-ends at $150 each times three equals around $450. The big money difference is in valves. Some riders don't have valve issues, but others do. If you do the valves are $433 (for all five) for the YZ250F and $167 for the Honda.So, the parts cost is not too far apart, but how much is labor? The price depends on the shop, but the cost of rebuilding a 125 top end is less expensive than the price of taking apart the four-stroke engine. Especially if you include the valve job. I won't even go into the scenario of breaking a rod through the cases on a four-stroke, which can cost more than the bike is worth to fix.There are also myths that four-strokes are harder on transmissions and chains and sprockets, but I personally couldn't attest to that. The bottom line, though, is that to the average racer every dollar counts, and the differences in maintenance may be the deciding factor in which bike to buy.Back to your question: Will we be running the 2006 125cc two-stroke shootout? Absolutely. It already appeared in the Winter issue of Mini Rider, and the April issue of DR will feature a similar test. Is there a Kawasaki in the shootout? No, because they aren't offering a 125cc in the U.S. any longer (and just to clarify, Kawasaki still manufactures the KX125; it is the American distrubutors who decided not to offer it in the states).The boys in Green won't really comment on this, but some say they shot themselves in the foot with this move. Why? All of Team Green's amateur support riders in the two-stroke-only schoolboy division are now forced to buy their bikes from our expensive neighbor Canada. Plus, the support for the KX125 isn't really there at the races, forcing a lot of kids to switch colors. With the new 144cc–legal two-stroke mods I spoke of earlier, a lot of riders could be coming back to mixing their gas, thanks to the lower costs of racing the bike.At the heart of this debate, Brian, lies a simple argument: Many four-stroke advocates claim that even a modified two-stroke can't beat an F. What do we think? Well, DR associate editor Jesse Ziegler is in the thumper fan club with Publisher Sean Finley, Karel Kramer will ride either as long as they are running well, Derek Steahly and I both mix our gas, and Editor Jimmy Lewis doesn't seem to care. But this still doesn't answer the question, is a 125cc two-stroke really slower than a 250F?I couldn't tell you for sure, but it never seemed to bother Bubba.Chris Denison
Editor, Mini Rider Magazine