( 5) Triple-clamp offset. No offense to triple-clamp manufacturers, but we never found an offset that worked better than the stock 22mm offset. Oh, don’t get us wrong; we could feel the difference—we just didn’t like it. ( 6) Tires. For our SoCal tracks, MXA test riders prefer a Bridgestone 403/404 combo or a Dunlop MX51 rear mated to an MX31 front. ( 7) Airbox mods. We run Twin Air’s $250 Power Flow airbox. It uses a green weenie-style air filter that flows more air, makes less noise and is slightly easier to change. Q: WHAT DOES THE 2013 YZ450F WEIGH? A: 237 pounds. It is lighter than the KTM, Suzuki or Kawasaki, but heavier than the Honda. Q: WHAT IS THE BEST ATTRIBUTE OF THE 2013 YAMAHA YZ450F? A: Reliability. This is a rock-solid machine. If you are racing on a budget and can’t afford any four-stroke catastrophes, the YZ450F is the best bike for you. Q: WHAT DID WE HATE? A: The hate list: (1) Airbox. How do we hate thee? Let us count the ways. It’s loud. It’s complicated. It’s wide. It’s the epitome of afterthought engineering. Believe it or not, Yamaha uses more bolts to hold the filter than the engine. ( 2) Weight. This bike would be so much better at 230 pounds, but even then it would still feel very wide. ( 3) Brakes. There is no crime in not having the most powerful brakes—but no honor in not having them, either. Q: WHAT DID WE LIKE? A: The like list: (1) Reliability. Unless a black cloud follows you around, the YZ450F will never break. ( 2) Spring preload. The shock preload ring is easy to get to. ( 3) GYTR Power Tuner. It’s more like a Playstation than a reprogramming tool. It is a small, relatively inexpensive, self-contained device that allows the fuel map and ignition timing to be changed in 30 seconds or less. ( 4) Clutch. Second only to KTM’s phenomenal hydraulic unit, the YZ450F clutch can take the abuse. Q: WHAT DO WE REALLY THINK? A: What can Yamaha do to restore the confidence in their brand that James Stewart destroyed? MXA does not believe that Yamaha has to throw the complete design away and start over—although we wouldn’t reject that idea if they had the R&D budget to support it. Instead, we believe that the 2013 YZ450F has a solid, working platform that may not have jived with Bubba’s strange suspension settings, but will work for 99. 9 percent of the racing public. It does, however, need some tweaks from the factory to go forward from here. What tweaks? (1) Fix the handling with new motor mounts, a longer swingarm or new frame geometry. ( 2) Broaden the powerband with mapping and more crank inertia. ( 3) Install a front brake that is as capable as KTM’s 260mm Brembo. ( 4) Do something about the atrocious airbox design (and its ultra-wide radiator wings). ( 5) Put it on Jenny Craig until it loses 10 pounds. ;
MXA YAMAHA YZ450F SETUP SPECS
This is how we set up our Yamaha YZ450F for racing. We offer it as a guide to help you find your own sweet spot. KAYABA SSS FORK SPECS Yamaha has the best showroom stock suspension sold. The Kayaba SSS suspension is so good that the MXA test riders had no major complaints. The damping keeps the forks high in their stroke so they maintain considerable travel for upcoming bumps. It is important that you get the chassis level by adjusting sag and fork height so that neither end is overloaded. For hardcore racing, these are MXA’s recommended 2013 Yamaha YZ450F fork settings (stock settings are in parentheses): Spring rate: 0.47 kg/mm Oil quantity: 355cc Compression: 10 clicks out ( 13 clicks out) Rebound: 9 clicks out ( 10 clicks out) Fork-leg height: 0mm up Notes: We had no major problems with the YZ450F’s Kayaba SSS forks. We prefer to run the compression setting stiffer than normal because it helps balance out the chassis and reduce the wiggle. KAYABA SHOCK SETTINGS Yamaha revised the rebound damping of the 2012 shock, so they didn’t touch it for 2013. Most MXA test riders slowed down the rebound to 14 clicks out, which would be comparable to the 11 clicks out that we ran back in 2011. For hardcore racing, these are MXA’s recommended 2013 YZ450F shock set- tings (stock settings are in parentheses): Spring rate: 5. 7 kg/mm Race sag: 100mm Hi-compression: 1-1/2 turns out (1-1/4 turns out) Lo-compression: 7 clicks out ( 8 clicks out) Rebound: 14 clicks out ( 17 clicks out) Notes: Most MXA test riders prefer less high-speed compression and more rebound. We also run a longer Pro Circuit shock linkage (not solely for suspension purposes, but also to give us more adjustment room with the head angle and frame geometry). The longer link will drop the rear of the bike almost 10mm, so you will need to slide the forks up to keep the bike level.
2013 YZ450F
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