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/491629
VOL. 52 ISSUE 14 APRIL 7, 2015 P47 has been beefed up to handle the extra abuse that off-road rid- ing often brings. Since the WR is EPA-compli- ant, its ECU is tamper proof and cannot be adjusted; if you do by replacing it, the bike is suddenly relegated to closed-course rid- ing only. The WR shares the same bilateral-beam aluminum frame and suspension components as the YZ. However, the suspen- sion, including the KYB 48mm air/oil separation Speed Sensi- tive System (SSS) fork, has been tuned for a slightly softer ride. Even though the WR and YZ share many of the same compo- nents, the WR has many of its own differences to make it more off-road friendly. As mentioned, it has a six-speed gearbox and electric starting. It also has an 18-inch rear wheel versus the YZ's 19-inch wheel. The WR is also fitted with head and tail lights, a kickstand, a plastic skid plate, a more powerful genera- tor and heavier generator rotor, a cooling fan, an intake baffle, a more restrictive (i.e., quieter) exhaust, and a throttle stop. TRAIL RATED Our test bike was delivered sans the intake baffle, exhaust baffle and throttle stop—all noise-relat- ed items—yet the WR is remark- ably quiet. The WR's USFS- approved muffler/spark arrestor does a fine job squelching unwanted noise without robbing all of its power. But first you have to start the bike, which is slightly easier now. The old WR had an on/off ignition switch, which has been eliminated on the new WR; now, you just hit the starter but- ton and go. The WR makes surprising good power for a Green Sticker bike. We probably should not have been too surprised, though; after all, it's the same motor that's in the super-fast YZ250F, but even with its restric- tive muffler and EPA-friendly mapping, the little WR really hooks up! It's no horsepower monster by any means, but it has decent zip for the casual trail rider. It has excellent bottom-end performance for just 249cc's, and it runs strong from midrange on up, too. What it may lack in YZ-type, hard-hitting horsepow- er, is made up for with greater tractability and smoother power delivery. Throttle response is good from its 10-hole 44mm Mikuni fuel-injection system, though we did notice a slight lean spot right off idle that was easily avoid- able by keeping the revs up and keeping a finger near the clutch lever at all times. Luckily, the clutch has a light pull, great feel and is as strong as an ox. We turned our WR into a closed-course race bike after removing the stock ECU and replacing it with Yamaha's acces- sory Competition Kit ECU, which is basically the same ECU that's in the YZ250FX. It comes pre- tuned for Yamaha's freer-flowing GYTR FMF-made muffler, which Yamaha assumes you'll be installing as well. We, however, stuck with the stock muffler and re-adjusted the ECU for it, using Yamaha's Power Tuner. The end result is significant. Not only did the lean spot go away, but we also noticed a huge boost in power in the middle of the powerband, and the dyno con- (Top) The WR is already fitted with a simple-to-use and useful enduro meter. (Middle) A sturdy plastic skid plate does a good job protecting the bottom engine cases and frame rails. (Botttom) Look familiar? The WR's motor comes straight out of the YZ250F but fitted with an electric starter and an extra gear.