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2005 HONDA CRF450R

Honda’s race-proven superstar, the CRF450R enters 2005 with a wealth of refinements and a lighter weight that make this big four-stroke the overwhelming class favorite. Features & Benefits New for 2005  New fourth-generation twin-spar aluminum frame. Forged aluminum steering head and tapered downtube section are designed to optimize frame rigidity. In addition, tall swingarm pivot plates and thin frame spars create a narrow overall frame cross-section for superb rider comfort and maneuverability. …

2005 HONDA CRF250R

Racing improves the breed, which means this class-leading front runner enters 2005 with a host of new features plus a lighter weight. Features & Benefits New for 2005  New cylinder head porting for increased power at lower rpm.  New camshaft profile increases low-rpm torque while maintaining maximum horsepower.  New ignition map works in conjunction with new cylinder head and camshaft for improved power at virtually all engine speeds.  New spark plug with side electrode for improved spark and co…

2004 YAMAHA YZ125

We normally ignore doomsday predictions. They never come true. Do you remember the Y2K hysteria, or the Nostradamus hype? There is, however, a new end-of-the-world scare! It is the much-hyped extinction of the two-stroke. Are we scared? No. Why not? Because no self-respecting motocross racer would move from a two-stroke to a four-stroke unless it was better. Two-strokes will thrive as long as they are competitive. And, when the day comes that they aren’t up to snuff, we won’t shed a tear if they join th…

WE TEST THE 2004 KTM 125SX

For the record, the KTM 125SX has the best two-stroke engine in the class. It puts most Japanese bikes to shame on the dyno, in first turn drag races, and up hills.

2004 HONDA CRF450

Honda isn’t taking the four-stroke movement lightly. When they first released the original 2002 CRF450, it had all the fixings of a great bike, but was missing a dash of low-end grunt, a pinch of reliability and a smidgen of accuracy. For ’03 Honda’s engineers changed the cam, redesigned the frailest pieces (air box, chain buffer and radiator wing) and, most of all, they steepened the head angle to sharpen the handling. Good fixes. But were the mods good enough that Honda could sit pat with the 2004 CRF…

SUZUKI RM-Z450 MAKES ITS DEBUT

All Japan MX Championship Sports Land Sugo, Miyagi Prefecture(Round 10 of 10) 1. Takeshi Katsuya Hon 1-3 2. Stefan Everts Yam 4-1 3. Kazumasa Masuda Suz…3-2 4. Yoshitaka Atsuta…Hon…2-4 5. Takesi Koikeda…Yam…7-6 6. Taichi Kugimura…Yam…5-11 7. Ryuichiro Takahama…Hon…6-13 8. Masaki Hiratsuka…Hon…12-10 9. Kuraudo Toda…Hon…15-8 10. Hisashi Tajima…Suz…14-9 11. Makoto Ogata…Hon…17-7 12. Manabu Watanabe…Yam…8-16 13. Takuma Kojima…Kaw…11-14 14. Takase Tanaka…Kaw…10-1…

SUZUKI TO DEBUT RADICAL NEW RM-Z450

FOR IMMEDIATE RELEASE       BREA, Calif., Aug. 29, 2003 – Suzuki Motor Corporation has announced it will debut its all-new prototype RM-Z450 four-stroke machine in the All-Japan MX series in October and will continue development in the World Motocross GP class in 2004 with a firm commitment to reclaim the world title with the new machine. Full details of the radical new RM-Z450 have yet to be revealed, but Suzuki promises that it will be a major step forward as Suzuki’s flagship …

KX250F REPORT – KAWASAKI ENTERS THE MIX

Riding the Green Machine By John Basher Everyone has been waiting with baited breath at the arrival of the new arsenal of 250 four-strokes, whether it is from Honda or Kawazuki. Wait, what’s that again? Kawazuki? Unless you’ve been living under a rock in the deepest and darkest caverns of earth (in which case you’re pretty far out of the loop), Kawasaki and Suzuki formed an alliance two years ago. By now you should be familiar with the terms of agreement between the two motorcycle manufacturers, and it …

INTRODUCING THE 2004 HONDAS

2004 CR125R Changes for 2004 ú New electronic power valve for optimum valve timing and improved power throughout the range ú TMX-x carburetor gets new throttle position sensor (TPS) for improved linear throttle response ú New quick adjust clutch perch ú New clutch lever to improve feel and action ú New aluminum Renthal Bars (971 Bend) ú New “non-slip” seat cover for increased rider control ú New footpeg hinges prevent dirt accumulation for consistent footpeg angle ú New Dunlop 742 front and 756 rear tir…

YAMAHA 125 INTRO-AN ONLOOKERS PERSPECTIVE

By John Basher As Tim Olson and I were cruising down the highway towards Glen Helen raceway on a beautiful Tuesday morning, I slowly began to see the track in the distance creep up on the horizon. It wasn’t my first time visiting the huge hills of Glen Helen, but today was different. I immediately discounted that the weather was different, simply because the weather is ever sunny at San Bernardino (or seems like it). I glanced in the rear view mirror, and then I remembered. With Tim at the wheel and myse…

2004 YAMAHA PHOTOS AND SPECS-

2004 YAMAHA YZ125 What’s new on the 04 YZ125? 1. The shape of the scavenging port and exhaust port is changed (the timing is also revised) 2. The setting on the YPVS governor spring is changed for better acceleration in the low to mid. 3. The carb setting at the bypass port is changed. 4. The exhaust pipe is increased in overall length by 5mm, mostly at the head pipe (not on European models). 6. The diameter of the stinger is increased 1.6mm (in front of the silencer) 7. The shift pedal is downsized 9mm…

2004 KAWASAKI PHOTOS AND SPECS

2004 KAWASAKI KX125 Kawasaki engineers succeeded in boosting overall power of the 2004 KX125 and revised the chassis for even sharper handling characteristics. *The combustion chamber of the liquid-cooled, 124cc, two-stroke single-cylinder engine is reshaped and compression increased to give it more low and mid-range power and crisper throttle response. *Aiding the enhanced throttle response is a new piston and ring, which has the piston ring locating pin at the rear of the cylinder to evenly distribute…

2004 SUZUKI PHOTOS

2004 RM-Z250 The engine was designed by Suzuki, but the full package is being produced by Kawasaki. The compact 249cc, four-stroke, liquid cooled engine features a four-valve head (the valves are titanium). The cylinder is plated aluminum and houses a forged, two-ring piston. Carburetion is via a 37mm Keihin FCR (with hot start and throttle position sensor) The lubrication system is a semi-dry sump with separate oil chambers for the crank and transmission, but shared oil. Five-speed transmission. Titani…

2004 CRF450R: IT’S NEWER THAN YOU THINK–MAY 13

The 2004 CRF450R has more changes than you might expect. Here are the key new features and some top-secret photos for you to check out: (Scroll Down For More Photos) NEW FOR 2004 1). New lighter piston is reshaped for increased compression, quicker response and improved torque over entire RPM range. 2). New Ignition cover made from new magnesium material reduces heat build up and reduces weight 3). New lighter ignition mass for improved response and drivability 4). New ignition timing for improved driva…

HONDA ANNOUNCES THE CRF250R TO THE WORLD

In a startling turn of events Honda has not only revealed the existence of their highly anticipated CRF250R, they have shown photos of it to anyone with an internet connection. It was originally thought that Honda would debut the bike at the last Japanese National with Ernesto Fonseca as the pilot, but instead they decided to announce the CRF250R at their annual dealer meeting. The bike is definitely a 2004 model so don’t get to excited yet, but after a few phone calls to Honda insiders we’ve learned th…

WRENCH TECH: HONDA CRF450 TRANSMISSION UPDATE

One of the nifty features on the 2002 Honda CRF450 four-stroke is the separated oil cavities. Unlike a normal engine, the Honda has distinctly different oil compartments for top-end oil and transmission oil. This is a great idea, although by no means new. By separating engine oil from tranny oil, a CRF450 owner can use specialized fluids for each task. There is no cross contamination from sheared-off clutch particles, gear flashing and valve seats. What’s the downside? The available pool of oil is great…

HOW TO GET YAMAHA SECRET YZ125 NEEDLE

The MXA test crew has used a special needle in its 2002 YZ125. The original MXA needle was a works part that was hand made. During testing, the works needle performed better than the stock YZ125 needle. Unfortunately, the hand-made needle was not available through Yamaha dealers. Yamaha’s engineering department, urged on by their own in house test results, decided to work overtime to make the secret needle available to American racers. They ran a test program, verified the results and had Yamaha of Japa…

2002 HONDA CR125

Honda released pics and specs on their 2002 CRs. Here is all the info you need to know! (click on photo) CR125: The new list: 1. New third generation twin spar aluminum frame and swingarm. (1.1 lb lighter than last years frame) 2. Redesigned rear brake system with integrated reservoir and master cylinder. 3. New 36mm Mikuni TMX-X carburetor 4. Air intake boot reshaped and boot volume increased. 5. Exhaust port reshaped. 6. Redesigned 8mm longer exhaust header. 7. Taller first gear ratio and closer spacin…

2002 HONDA CR450F–APRIL 30

CRF450: 1. New third generation twin spar aluminum frame. (1.1 lb lighter than last years frame) 2. Redesigned rear brake system with integrated reservoir and master cylinder. 3. New Unicam valve train. 4. Pin-rotation type auto decompression release. 5. Hot start system. 6. Two 36mm titanium intake valves. 7. Two 31mm steel exhaust valves. 8. 96mm x 62.1mm bore and stroke. 9. Twin-sump lubrication system separates the oil supply for the crankshaft, piston, and valve train from the clutch and transmissi…

2002 HONDA CR250

(click on photo) CR250: 1. New third generation twin spar aluminum frame and swingarm. (1.1 lb lighter than last years frame) 2. Redesigned rear brake system with integrated reservoir and master cylinder. 3. All-new case-reed engine. 4. RC-style exhaust valves (similar to the CR125) with as electronic control module that uses engine rpm to calculate exhaust position and signal a DC servo motor to adjust the RC valve. 5. Magnesium clutch cover. 6. Showa suspension front and rear. 7. Aluminum spoke nipples…

YAMAHA DEBUTS THE YZ250F

Amidst all the hype surrounding the first outing of Honda’s RC450, Yamaha also debuted a new bike at the October 22nd race in Japan. That’s right, at the same mud race where Tortelli showed the world the RC450, Ernesto Fonseca proved to the world exactly what the YZ250F was capable of after months of rumors. Ernesto holeshot both motos and after a small battle with the locals, pulled out to a ten second victory in moto one and a twenty second victory in moto two. On hand at the event was the very proud …

SEE IT NOW! HONDA’S NEW FOUR-STROKE

Honda is a strange company. Less than a month ago they refused to tell or show their dealers any details on the CR450 four-stroke at the annual dealer meeting in Las Vegas. Now, they bring the bike out in public at this week’s Japanese race and allow a hoard of photogs to snap photos at will. Strange marketing! Honda dealers could have used the promo material on next year’s CR450 four-stroke to increase floor travel (and been in the know before their customers). HERE ARE THE CR450 FACTS The CR450 engine…

YAMAHA’S ALL-NEW 250 FOUR-STROKE

Believe it or not, Yamaha will race a four-stroke in the 125 class next year. No, not a 125cc four-stroke—a 250cc four-stroke. Under current AMA rules the 125 class is limited to 0-to-125cc two-strokes and 0-to-250cc four-strokes. The all-new Yamaha YZ250F (the F stands for Four-Stroke) is a down-sized version of the popular YZ426 (which is 250 class legal). But do not think that the YZ250F is a clone of the YZ426. In fact, it shares very few engine components with its big brother. Few engine parts ar…

2001 HONDA CR125 & CR250

Want to know what’s different on the 2001 CR125 compared to the CR250 other than a smaller motor? HERE’S WHAT’S NEW ON THE 2001 CR250 1. New cylinder port shapes and timing specs provide a smoother and stronger power delivery, and produce lightning-quick acceleration. 2. All-new lighter 38mm flat-slide Mikuni TMX carburetor adds both initial throttle crispness and improved throttle response to complement the new engine character. 3. New reed-petal stopper shape improves mid-range and high-rpm power deli…

FOOLPROOF STARTING TIPS FOR YZ-F OWNERS

There is no doubt that the Yamaha YZ-F will encourage lots of new riders into the four-stroke fold. The rite of passage for any neophyte four-stroke rider is starting one of the beasts. The golden rule–tattoo this on your forehead is: “Thou shall not touch the throttle at any time during the starting process.”  If you are smart, you will do exactly what we tell you. If you’re not smart…good luck.  Step one: With the transmission in neutral, turn the gas on and pull the choke out.  Step…

2001 SUZUKI RM125!

Want to know what next year’s RM’s will look like (about six months before they release them)? Look no further. The 2001 RM’s will feature a totally new gas tank, new radiator wings, side panels, fender and front number plate. Insiders report that Kayaba will get the suspension contract for the 2001 RM250, but MXA’s spy photos reveal Showas on the 2001 RM125. Look for an external water pump, which will require new cases on both the 125 and 250. The 2001 engine is totally redesigned. The most noticeable …

MXA’S SECRET JETTING SPECS, 2003 And Back

We can’t tell you how to jet your bike. It’s a big world out there (and we don’t know you all that well). However, we can tell you what jetting we run in the MXA test fleet. Take into account that we race in a Mediterranean climate, near sea level, within sight of palm trees and never far from a Double Latte. We also run fresh 92-octane gas, work on our bikes every week, clean the filters, change pistons and rings regularly, are alert to pinging and haven’t changed oil brands in over a decade. This is t…