Staircase: The downdraft throttle body is a byproduct, not a goal.
engendered scorn with a bike that was poorly thought out and obviously rushed into production. That is the bad news. The good news is that Yamaha’s engineers had four years to repent for their sins, and the 2014 Yamaha YZ450F is a bike built by men desperate to make amends for their previous transgressions. They had something to prove and their own reputations to save. The 2014 Yamaha YZ450F, while not perfect, is a much-improved bike this time around. This is a better Yamaha YZ450F. Making it the best 450cc motocross bike is up to you and your setup skills. ;
SETUP SPECS This is how we set up our 2014 Yamaha YZ450F for racing. We offer it as a guide to help you find your own sweet spot. KAYABA SSS FORK SPECS Yamaha is smart enough not to try to reinvent the wheel when it comes to suspension. While the other manufacturers scramble to find a semi-sweet spot, Yamaha has been sitting on the mother lode since 2007. Why mess with success? For 2014, Yamaha increased the rigidity of the upper stanchion tubes by 3 percent, polished the fork tubes to a higher sheen for better seal life, increased low-speed damping, enlarged the front-axle from 20mm to 22mm, upped the spring rate (from 0.48 Nm to 0.49 Nm), and lowered the oil height. For hardcore racing, these are MXA’s recommended 2014 Yamaha YZ450F fork settings (stock settings are in parentheses). Spring rate: 0.49 Nm Oil quantity: 335cc Compression: 11 clicks out ( 9 clicks out) Rebound: 8 clicks out Fork-leg height: 4mm up Notes: Our Vet and Novice test riders thought the forks were on the firm side and turned the compression clickers out. The Pro test riders thought the forks were too soft and added 10cc of oil (but ran the same compression settings as the Novices). The oil height is lower in 2014, but because of the stiffer spring, which adds compression resistance and displaces more oil, the 20cc-lower oil height is not as dramatic as it seems. It is important that you get the chassis level by adjusting sag and fork height so that neither end is overloaded. KAYABA SHOCK SETTINGS Because of the extra room found when moving the exhaust pipe forward, Yamaha was able to relocate the shock’s piggyback reservoir—from sideways in 2013 to vertical in 2014. This change doesn’t have any major effects on performance, but it is easier to work with. For hardcore racing, these are MXA’s recommended 2014 YZ450F shock settings (stock settings are in parentheses). Spring rate: 5. 8 Nm Race sag: 105mm (100mm) Hi-compression: 2 turns out (1-1/5 turns out) Lo-compression: 12 clicks out Rebound: 9 clicks out ( 14 clicks out) Notes: Yamaha stiffened the shock spring and changed the damping to accommodate the spring change. The shock is configured to work better for heavier and faster riders. Most MXA test riders preferred a lot more rebound damping. As for the race sag, we ran it low until we installed the longer, 143.5mm Pro Circuit shock linkage— although 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 8mm, so you will need to slide the forks up to keep the bike level.
Setup: We lowered the rear of the YZ450F because it was high.