KTM's 2004 300 E/XC is as new as a motorcycle can get. It's based on the 2003 KTM 250 SX, which was adapted from KTM's 2002 MXGP works bikes piloted by James Dobb, so it really can't be compared to the '03 300. Dobb's race bike represented the first all-new KTM 250/300 design since 1990. The company took the opportunity to build more power, cleaner shifting and a lower seat height into a package that is super-light. One of the best things about KTM is that very little is lost during the transformation of a new motocross model into an enduro/cross-country machine. KTM currently has the lightest 250cc two-stroke motocross machine you can buy. Knowing that fact, and how closely related KTM motocross and off-road models are, we were still shocked at the readout on Dirt Rider's dual-pad digital scale: 227 pounds! That isn't some "claimed" dry weight; we weighed it ready-to-ride but with the tank empty. That is extremely light for a fully equipped off-road (closed-course) race bike and within a pound or two of some 250cc motocrossers! For comparison, the old Suzuki RMX250 weighed 249 pounds, a Kawasaki KDX200 weighs 240 and a Yamaha WR250F, a Honda XR250R and a Kawasaki KLX300R all weigh about 250.The best part is the KTM isn't just light, it's totally right for serious off-road racing. This bike needs only heavy tubes and hand guards to be race-ready anywhere.With all the changes, the 300 looks very purposeful and race-ready, and it is. We ran the bike through the gamut of terrain in our area. We started on the packed clay, shale rock and decomposed granite at Rowher Flats (Texas Canyon), roosted through the trails of Lake Arrowhead from the Pinnacles staging area, hit the starting line for two classes at the Lake Elsinore GP then headed for the steep and sandy high desert of Red Rock Canyon and Dove Springs. We experienced no need to play with the jetting despite the radical changes in altitude. For Elsinore we swapped the stock Bridgestone M59/M402 tires for an M401/M402 combo with Bridgestone heavy tubes, then installed Enduro Engineering hand guards and a GPR steering damper. The wide-ratio five-speed had a gear for every situation, and we rarely ran out of speed in fifth gear or found that first gear was too tall. There were times, mostly in the high desert, when the ratios felt a tad too wide for maximum fun, so we would gear a little lower for tight riding, where losing top speed wouldn't hurt as much. It's not that the engine isn't perfectly capable of pulling through the semi-wide spacing of the ratios, but more a case of finding the engine out of the happiest part of the power climbing decomposed granite hills, when dropping down a gear would be too low. We did have a 120/100-18 Kenda Southwick tire on the back, and no doubt the stock Bridgestone rear or a less-aggressive Kenda would have let the engine pull a tall gear more easily. The Southwick is the next best thing to a true paddle tire, and has motivated us to run lower gearing in the past.The engine is strong but so smooth that it is more four-stroke-like than some four-strokes. Starting is also perfectly easy and reliable. Older 300s started readily but took some muscle to kick; the new bike kicks easier and starts readily. As with all '04 KTMs, the 300 gets a clutch master cylinder with a 1mm-smaller bore. The new unit has a lighter pull but with the same easy, crisp engagement for which KTM's hydraulic clutches are known. There is a little engine vibration, but otherwise we can't fault the powerplant.At Texas Canyon we climbed some steep, rutted, rock-garden hills. Getting a run was not an option, and we had to crawl up through rocks on a steep hill using the power and the clutch to get through. We had four-strokes along that typically excel in similar circumstances, but they boiled over, stalled and required massive clutch slipping. The 300 E/XC, with its tractable power, light weight and low first gear, made them all look silly.The Lake Arrowhead trail system is fairly limited in terms of mileage for bikes without license plates, but the altitude makes it a tempting destination when the valleys are too hot. In addition, riding through the trees the views are great, so there is enough traffic that the trails can be rough with whoops, rocks and roots, and sometimes all three at the same time.We brought along a 525 E/XC four-stroke as a measuring stick. The two were something like a Cadillac and a Mustang GT. The 525 is plush and smooth with a somewhat-long feel to the chassis. The 300 acts much lighter and has snappier manners and responses, plus the suspension is crisp and rides up in the travel compared with the 525. The 300 is close to the 525 in power delivery; both are smooth, but the four-stroke is more torquey. The 300 is quicker revving, but you need to shift it more often; the 525 pulls longer in each gear. When we went to the high desert, we also had a 250cc motocrosser along. That was a fairer comparison than the 525, and the 300 was all that you would expect. It climbed hills as if it had more peak power, but the engine also made a lot more meat in the middle rpm ranges. Riding the 300 was less work, since you make good trail speed at a lower rpm. On tight trails that fat 300cc midrange pull often allowed the rider to accelerate from a corner without shifting when that would be impossible on any 250. Of course, since the KTM is an E/XC--made for enduros--it had smooth torque from right at idle on up. There was not what motoheads call "hit," but a touch of the clutch did snap the engine into the meat of the midrange. As with the best years of the KTM 300, this one doesn't really feel fast--until you notice you are constantly blowing by your buddies on 250s. When conditions are tight or uphill, you can moto by so quickly it nearly rips the stickers off the bike.The handling and suspension are as excellent as the engine. The combination of the 48mm WP fork, the oversize front axle and the rider-forward ergonomics had this E/XC cutting a line through tight trails that past KTMs only dreamed of. The seat height is not objectionable, so that also helped the handling.After a ride on the 300 E/XC, you'll be spouting T-shirt slogans, since the bike invites superlatives. A couple we think apply are: "It doesn't get any better than this" and "If you can't run with the big dogs, stay on the porch."