Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128130
Yamaha WR250F Kyle Parson's highly modified WR250F proves that more power can be found in the IitUe WA. But Is it enough? ne an's &lore a""er ou~ aying that the WR250F is underpowered is pretty much an understatement. Unfortunately, the stringent emissions standards that the manufacturers are forced to comply with in order to sell off-road-Iegal dirt bikes to the public simply kills engine performance, especially when it comes to Yamaha's YZ250F-based WR250F. This becomes painfully obvious after riding the YZ250F, which is, for all intents and purposes, propelled by the same motor that powers the WR but has seemingly twice the muscle. Disconnecting, okay cutting, the infamous "gray" wire in the WR's ignition helps, but the WR needs a lot more than that to make the bike acceptable for off-road competition use, or even for semihardcore off-road trail riding. The WR simply needs help. And we found one that had been helped. Kyle Parsons, of Klotz Performance Lubricants, offered us a chance to ride his own highly modified WR250F that he said now performs the way S NOVEMBER 14, 2001 • cue 0' ~"e MlRZ5 the WR should, before the government got its hands on it. Parsons went all out on his WR. He had Millennium Technologies bump up the displacement to 263cc (2mm over-bore) and had J. Jones Racing modify the head and readjust the cam. He also installed an adjustable Vortex Ignition System from MT Racing, had K.P. Cryogenics strengthtreat the motor's internals, and replaced the stock piston with a Wiseco 2mm over-piston kit. Finishing off the engine mods was a Dubach Racing Development exhaust STORY AND PHOTOS BY KIT PALMER 42 es~ ~o ge~ system. Parsons also went all out on the bike's suspension and chassis, such as revalving the for~ and shock, and coating his bike with numerous other cool aftermarket components: every kind of guard you could think of, Zip Ty Racing's hot-start replacement set-up and Ceet graphics. Heck, just about every part on Parson's bike got modified, replaced or removed. But our main interest about this bike was it's motor. Could more power be found? That's what we wanted to know. After all, we already • III "IlI_S know that the WR handles well and has top-rate suspension. We took Parson's WR to our favorite local riding spot and gave the bike a good workout. We found that his bike is indeed a harder-hitting machine and far more capable than a stock WR. The bike works best when it's ridden assertively and kept in the upper rpm range, rather than trying to lug it from corner to corner as you would with a bigger-displacement offroad machine. Basically, you still have to ride it like a 125cc two-stroke, but at least you're now rewarded with some more muscle on top. Yes, Parson's WR has more power than stock; that much is true, unfortunately it still leaves you wanting more, mainly more bottom end. As a result, you have to keep this motor pinned at all times, and you have to ride the clutch hard when the trail gets real tight. By no means is this a lazy man's bike; you can never relax and sit back and let torque carry you from one turn to the next, because the bike has none. Instead, you ha'(e to be super aggressive at all times to make the WR work properly and effectively. In spite of all of the engine mods, Parson's WR was about as easy (or perhaps more appropriately difficult) to start as a stock WR. In 'other words, about the same. The Zip Ty Racing hot-start system, which relocates the operating mechanism from the carb to the left handlebar, makes the starting regiment easier, but Parson's WR was still a finicky starter. Pretty much our only real complaint with Parson's WR during our short ride on the bike was the overly loud exhaust system. Yeah, it might give the bike more power, but it comes at a cost, as it doesn't do much in the way of muffling. Overall, Parson's highly modified WR250F runs circles around a stock WR, but it's still no horsepower monster by any means. At least we know now that a WR250F can be made to be competitive. But, boy, did it take a lot of work. Luckily, we didn't have to do it. eN Keep it pinned and the WR moves along pretty good. Just don't get lazy.