A year into its life and our 2010 Yamaha YZ450F is still ticking like a clock (a good one) and making riders happy (as long as they like an easy to ride, plush and tight steering bike). Our major modifications have stuck with the bike since we really like they way they work and they are proving every bit as durable as the stock components they replace.
The Akrapovic (www.akrapovic.com) exhaust system still continues to be our favorite for the bike, but that has not stopped us from testing a newer FMF 4.1 system. It gives the bike a little more punch on the bottom, highlights the mid and even allows the bike to rev more than stock, making for an excellent overall improvement and would definitely make riders happy for a couple of reasons in comparison to the Akro system. It is much less expensive and it has more on the bottom if you like that sort of boost. The Rekluse EXP clutch (www.rekluse.com) makes stalling a rarity and pulling hard out of turns a gear high a cinch. Lately it feels like it is slipping a bit more than when it was new, but an inspection of the clutch plates showed this was not the case, at least from a wear or heat standpoint. We will look into this further and see if the expanding plate in the EXP has softened or needs to have some of the springs changed or replaced. Most love the added plushness provided by the Fasst Co. Flexx bars (www.fasstco.com) but some riders really feel the additional weight they bring into the steering of the Yamaha and can’t get over that.
The rear of the bike has been treated to a TM Designworks smorgusborg of chain and brake protection which has replaced some well worn stock components and made the bike look better too in the blue color. The chain and sprockets are next on the list and we have some GYTR stuff ready when needed.
About our only hiccup so far has been with the DT1 air filter. We did a poor job oiling the foam one time and allowed it to pass a small amount of dirt. Now we take the majority of the blame here, since proper oiling would have eliminated the problem, but the foam is a little more course than the stock filter and may have made it easier for dirt to pass, in our opinion. Now we will see how tough the Yamaha top end really is, as small amounts of dirt are the catalyst for valve issues. We are watching the clearances closely and ready to act the minute the starting becomes difficult, which it hasn’t.
At roughly 60-hours we finally took the suspension to Graeme Brough (310/809-8014) to get it serviced It was definitely needed attention. The freshening cost $300 for the service plus parts, which totaled $160 for both front and rear, including seals, some bushings and oil. Right away the bike was less springy and used less stroke on the bigger impacts, like it used to be. We may have waited a little longer than we should have but that goes to show the Yamaha can take it.
Were putting massive hours on the bike now and Yamaha is so confident in the YZ450F they have agreed to let us do the total and complete teardown on the bike for the wrap-up, so look for that in a future issue of the magazine. So far they have received minimal complaints, if any, from the revolutionary new design and we are on track with seconding that opinion.