In a nutshell, the Yamaha WR450F is a cheap performance dirt bike with a reputation for being a lot more bullet-proof than its competitors. First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model. In 2001 and 2002 the WR426F was released, then the third generation was the WR450F from 2003 with the bigger engine, smaller fuel tank and an electric start. Most changes since then have been minor, except for the alloy frame from 2007, and the 2012 model has gone to fuel injection and finally got the beefy suspension of the YZ models installed.
The WR450F is basically the YZ450F detuned slightly for more controllable power, with a headlight and lighting coil, softer suspension, a kickstand, lower noise specifications, larger radiators and lower emissions. The WR in the name indicates a wide-ratio gear box common to most enduro or trail bikes and stands in contrast to the close-ratio gearbox essential to a motocross racer.
Let's have a closer look at the pros and cons of the WR450F and WR250F. Click here for a WR450F video.
GOOD STUFF ABOUT THE WR450F
PROBLEMS WITH THE WR450F
* Still only a five speed gear box (get with the program Yamaha!)
* Suspension will be soft for heavier riders, or really hard riding
* No handguards
* Bottom power is soft with quiet pipe, but it has a big hit.
* Woodruff keys were a problem on some 2003 models (read more here)
* Hard working on the carburetor with the bulky alloy frame on 2007+ models
* Yamaha pinch pennies on their grease - regrease your head bearings, the swingarm bearings and the shock linkage.
YAMAHA WR450F & WR250F MODS & TIPS
GTYR DERESTRICTION KIT
Like all street legal dirt bikes, the WR450F comes restricted and you will probably want to make some, if not all, of these mods. GTYR sell a derestriction kit that includes a short throttle stop, AIS removal bits, new jets, and instructions for around $40. There are brilliant pics and instructions here. You can remove the airbox snorkel and enlarge the opening, but make sure this suits whatever rejetting you do on the carburetor (full jetting charts here).
What's the AIS? Air Induction System, an environmentally friendly thing from the 2005 models on. Removing it won't increase performance, but does decrease decel popping.
GREY WIRE REMOVAL
EXHAUST PIPE MODS
Next mod? You can buy the GTYR replacement exhaust tip which provides a wider diameter pipe for around $55. The bike will have a bark when cranked, but it still passes the 96Db stationary test. Plus you can always whip the stock insert back in if you need to ride in stealth mode near houses.
After that, you can either modify the internals of the stock pipe, or go for aftermarket pipes, but the WR will definitely be loud. One thing to consider, some guys simply like making lots of noise, but often the assumed extra power you are getting from aftermarket pipes is largely psychological - it sounds louder, so it MUST be faster. Dyno charts often show only a small increase compared to properly modified stock exhausts (plus unless you are in the top 1% of riders, extra power often makes you a slower rider except in a straight line drag).
SETTING UP THE WR450F AS AN ADVENTURE BIKE
* 15/45 gearing or similar for highway cruising
* Rekluse auto clutch for a usable first gear in gnarly territory ($450)
* Add a Jagg oiler or make an auxiliary oil tank for less oil changes
* Dunlop D606 tyres or similar
Fit a DRZ400SM 310mm front disc and caliper adapter for road braking
* Adapt a Husky TE610E rear wheel for the cush drive hub (info here)
* Fastway Pro moto billet packs and fender packs
* Acerbis 6.6 gallon tank, or smaller Clarke tank
* HID headlight and/or auxiliary LED driving lights
* Repad the seat yourself, or get an aftermarket one like the SeatConcepts.
Let's face it, the WR450F will not make the perfect adventure bike, you need the extra engine capacity. But if you want to ride gnarly trails, but also do the longer trips then these mods will give you a surprisingly capable bike with low maintenance intervals. A major point is the five-speed gearbox which doesn't have very wide ratios, but a Rekluse auto clutch makes an incredible difference if you want to opt for high gearing but still do slow tough riding.
While we found the Rekluse EXP auto-clutch to be a great piece of equipment, we did run into problems with the clutch slipping in higher gears at lower revs. You can read our Rekluse EXP test, issues and problems review.
MOTARDING THE WR450F & WR250F
If you are on a budget, there are cheap Chinese motard wheels on Ebay for around $600 which should be fine for non-racing use. A great budget option is adapting cast wheels which also gives you the cush drive hub, click here for info on adapting Honda cast wheels.
If you are racing, or otherwise going to be giving the wheels a pounding, it's usually best to only look at the quality gear and fork out the big bucks.
RESIZING THE WR450F TO FIT THE TALL AND SHORT
Are you vertically challenged? You can raise the forks in the clamps and buy a lowering link for the rear from a place like Mountain Motorsports. Budget method, and it may affect yoru handling. Otherwise get a suspension shop to do it.
If you are very tall (e.g. over six foot) you'll probably feel cramped on the WR. You can fit bar raisers and high bend bars on the WR without needing new cables. You can repad the seat so it is higher (and more comfortable). Also, there's a very simple free mod you can do to your stock pegs to move them back and down a bit for a bit more room on the bike (here).